SimuTerra
Frequently Asked Questions
Topics
General
Download
Import
Export
Saving
File and Data Formats
Objects
Polys
Entels
Layers
DTM
Roads
Views
Miscellaneous
GENERAL
Where else can I look for assistance?
What version of SimuTerra does this FAQ apply to, and when was it last modified?
DOWNLOAD
I try to download the installer but end up with a page full of code; what should I do?
Why does the name of the installer which I downloaded look odd?
LICENSING
Can I try the program for free?
Will the trial copy expire?
How do I get and use keys?
Can I try the program without getting keys?
What are the differences between the limited trial, the 30-day trial, and the purchased copies?
Is there a student version or an educational license?
Does SimuTerra come with a user manual or other documentation?
IMPORT
What kinds of files can SimuTerra import?
Can I import from SketchUp?
What can SimuTerra import from a DXF file?
What is meant by tabular data?
Can SimuTerra import data in a grid form?
Does SimuTerra import layers?
Should I import a DXF file of contours directly into SimuTerra, or first into SketchUp and create a foam core model?
Can there be gaps in imported contours?
EXPORT
Can I export roads?
What kinds of things can I export?
Can I export just the changes in the terrain?
Can I export points?
Why are there holes in my export?
Can I export contour lines?
Can labels be exported?
What is a polyface mesh?
What export entity option(s) should I use?
Can I change the size of the grid squares?
Why do I see triangles when I import a square grid into another program?
Why does the DTM seem to be incorrectly scaled when I import it into another program?
Which version of SketchUp is compatible with SimuTerra.
Why are the triangles which are imported into and displayed in SketchUp slightly different from those exported by SimuTerra?
Can one export Simuterra contours to a 2D CADD program to use as a basis for a grading plan?
SAVING
Why is the Save menu item not enabled in the File menu?
What happens when I save a file?
Why is the File > Save menu item enabled even though I've just saved?
FILE AND DATA FORMATS
Are SimuTerra files cross-platform?
What can I do with data from a 2D CAD program?
OBJECTS
What is a modifier?
What is a collar?
Can object labels be displayed?
How do I know the elevation of an object?
Can I edit elevations of objects?
Can I place objects on the surface?
Can I duplicate objects?
Can I copy/cut/paste objects?
Can I scale object coordinates?
What is the snap feature?
POLYS
Can I edit individual vertices of a poly?
Is there a way to individually adjust vertex points on a poly numerically, such as for a road?
Can I filter polys?
Can I join (merge, splice) polys?
ENTELS
What is an entel?
What purpose do entels serve?
Can I create or import my own custom models to use as entels?
Can I import ready-made models from another source for use as entels?
What kind of animation is there?
Can I resize or scale the entels?
LAYERS
Does SimuTerra have layers?
DTM
What is a TIN?
What is a DTM? A DTM set?
How do I know if an object is part of a DTM?
What do convex and concave refer to?
Why is there more than one menu item for creating a DTM?
Can SimuTerra show contour labels?
Can I rotate contour labels?
Why is the DTM > Create DTM menu item disabled?
Is there a limit to the size of the DTM?
What is a breakline?
Can I use breaklines?
How is SimuTerra different from using a topo-related Ruby script in SketchUp?
Can I create a DTM from a SketchUp foam core model?
Why are there inconsistencies along the edge of a DTM created from a SketchUp foam core model?
Why doesn't the DTM go all the way to the corner of the SketchUp foam core model?
Can I see the square grid before I export it?
Why doesn't the square grid cover all of the area of the DTM?
What if I want some data to NOT be part of a DTM?
Do imported contour lines have to be continuous or at regular intervals?
What's the difference between using points and using polys when creating a DTM?
What is the purpose of the various DTM numerical parameters?
Can I simplify the terrain (reduce polygon count)?
Can I create a DTM from 2D data?
What is a Cut & Fill DTM?
Can SimuTerra show triangulation?
Can I drape a texture or photo onto the model?
Can I make a swale?
Can I make a building pad/slab?
How should I deal with a building footprint or a building?
Can I make a parking lot?
How do I know the elevation at a particular location?
Can I determine the slope at a particular location?
Can I have a hole in my contour map?
What do cut & fill volumes represent, and how are they calculated?
Can SimuTerra make "foam core" models or rather just meshes?
ROADS
Can SimuTerra do roads?
Is it possible to color or texture a roadway?
Can I extrude a cross-section along a road, such as for pavement and curbs?
Can I import a road?
Can I set the slope of a road?
Can the sides of a roadway be at different elevations, i.e., can the road be superelevated?
Can the width of a road vary, such as in a transitional section?
VIEWS
Why would I want more than one view of the same document?
Can I select data in a 3D window?
Can I hide certain types of items in a view?
MISCELLANEOUS
Does the cursor ever change?
What units of measure are available?
Why is the sound volume low on web site videos?
Why is there more than one tool for selecting objects?
How can I speed things up? (too many vertices on polys; smaller 2D window; fewer windows; turn off animation)
Can I do grading plans?
Any solution for surveying, coordinate geometry (COGO), deed plotting, and the like?
What programs is SimuTerra compatible with?
Why does it sometimes take a long time to open a SimuTerra file containing a DTM?
GENERAL
Where else can I look for assistance?
* How-To's, which explain how to accomplish various tasks.
* Troubleshooting.
* Movies.
* Built-in help.
* Help material on web site (same as built-in help).
* Help tags (tool tips).
* Status bar (in Windows version).
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What version of SimuTerra does this FAQ apply to, and when was it last modified?
This FAQ applies to SimuTerra version 1.1.19, which was released on May 12, 2005. The FAQ was last modified on May 12, 2005.
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DOWNLOAD
I try to download the installer but end up with a page full of code; what should I do?
* Macintosh: Hold down the Command key when you click on the link.
* Windows: Right click on the link.
* Choose "Download linked file as..." (or something to that extent) from the menu which appears.
* Choose a location where you would like the installer file to be downloaded to.
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Why does the name of the installer which I downloaded look odd?
If you downloaded the file onto a Macintosh running Mac OS 9, the name may be truncated and may have other characters added to it. It should still work fine.
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LICENSING
Can I try the program for free?
Yes. It costs nothing to download the installer and to install SimuTerra. Once installed, SimuTerra will operate in the limited trial mode (no save; holes in DXF output; watermark in printout). You can also ask us for a pair of keys for the free 30-day trial at Pro level (no limitations).
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Will the limited trial or trial copy expire?
The limited trial will not expire, though it may grow old as we come out with newer versions. The free 30-day trial will expire 30 days after we issue the keys.
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How do I get and use keys?
Complete instructions for this are on our web site (http://www.compuneering.com/simuterraHowToObtainAndUseKeys.php). In short, you install SimuTerra, use it to get the system signature, send it to us, and we provide you with the license and activation keys.
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Can I try the program without getting keys?
Yes. Download the installer, then run the installer. The program will run in limited trial mode (no save; holes in DXF export; watermark in printout) until you get and use keys.
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What are the differences between the limited trial, the 30-day trial, and the purchased copies?
Complete information can be found at http://www.compuneering.com/simuterra.php. In short, the limited trial is limited in that it cannot save, it leaves holes in DXF export, and it places a watermark in printouts. The free 30-day trial has no limitations, but will revert to the limited trial mode 30 days after the keys are issued. If you purchase the program, we give you keys which don't expire.
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Is there a student version or an educational license?
There is no special student version. But you can use the limited trial for free. We offer drastic discounts to students and instructors, and we offer site licenses for educational institutions. More details can be found by clicking on the "Educational" link on our web site.
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Does SimuTerra come with a user manual or other documentation?
Nothing printed. There is, however, a built-in help system: choose Help > SimuTerra Help (Macintosh) or Help > Contents (Windows). The same content is available on our web site as well. More information should appear in a How-To section on our web site, if it isn't there already.
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IMPORT
What kinds of files can SimuTerra import?
Two kinds of files: DXF, or tabular data. In either case, it must be a text (ASCII) file, which can be open and read by a word processor. Again, a DXF file would have to be text, not binary.
At this point, SimuTerra cannot import or read USGS, DEM, DWG, Exterior3D, LANDesign, etc. There are, however, other programs which might help. For instance, if you have a DWG file, you can import that into a CAD program or a program such as SketchUp, then export the information to a DXF file.
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Can I import from SketchUp?
Yes. You need to export your model (edges only) from SketchUp using DXF, which SimuTerra can then import.
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What can SimuTerra import from a DXF file?
SimuTerra can make use of the following DXF entities: POINT, POLYLINE, LWPOLYLINE, LINE, and 3DFACE. The entities would have to be on their own, not inside of blocks.
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What is meant by tabular data?
Tabular data is data in table format, in a text file. SimuTerra can import tabular data (such as x,y, and z, or point number, northing, easting, elevation, description), and the data can be Tab- or comma-delimited. This would all be in a text (ASCII) file, which can typically be opened by a word processor or a spreadsheet program.
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Can SimuTerra import data in a grid form?
No, but perhaps a macro could convert the data into a form which SimuTerra can import. Contact us with specific requests.
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Does SimuTerra import layers?
Yes. Any entity which is imported from a DXF file, and which has a layer specified for it, will be placed in that layer. If no layer exists by that name, then one will be created.
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Should I import a DXF file of contours directly into SimuTerra, or first into SketchUp and create a foam core model?
It is usually much easier to import directly into SimuTerra, and will usually give better results. SimuTerra can use various bits of contour lines, whereas SketchUp requires that there be no gaps so that faces can be created.
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Can there be gaps in imported contours?
Yes, in two senses. There can be spaces between multiple contour lines representing the same elevation. And there does not need to be any regular interval between the elevations represented by the imported data.
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EXPORT
Can I export roads?
Yes, in a few different ways. With any level of SimuTerra you can export road footprints or extrusions. (Road footprints include outlines of the road.) With the Pro level you can also export the Proposed DTM minus the Existing DTM, which could yield the road itself.
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What kinds of things can I export?
Not everything that you see in SimuTerra can be exported. You can export points to a tabular text (ASCII) file, and you can export various items to a DXF file. You can export a DTM, which means that the entire surface gets exported, either as triangles or as a square grid. You can export the 3D contours. The difference between Proposed and Existing DTM can be exported by the Pro level. Road footprints can be exported, as well as road extrusions. Entels, imported polys (polylines) and textures cannot be exported.
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Can I export just the changes in the terrain?
Yes, with SimuTerra Pro. You create both an Existing DTM and a Proposed DTM, where the Proposed DTM is created by using modifiers such as roads and building pads. You can then export the difference between the existing and proposed.
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Can I export points?
Yes, you can export one or more selected points to a tabular text file, which can then be read by spreadsheets, SimuTerra, and other programs.
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Why are there holes in my export?
When you export from SimuTerra when it is running in the limited trial mode, it skips about a third of the triangles and contour lines. But each triangle that it does export should be a complete, closed triangle.
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Can I export contour lines?
Yes. But in order to do so, you must use the Info Panel to indicate to the DTM that contours should be displayed in 3D. Then, when you choose File > Export DXF..., contours will be in the exported file.
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Can labels be exported?
No, neither object labels nor contour labels.
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What is a polyface mesh?
This is a special case of a POLYLINE entity in a DXF file. When SimuTerra exports triangles (or a square grid, which is actually composed of pairs of triangles), it can group them all into one entity which is referred to as a polyface mesh. Programs which can read DXF can typically understand a polyface mesh. SketchUp, for instance, prefers to receive the triangles as a polyface mesh. SimuTerra can export a polyface mesh, though it cannot correctly import it.
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What export entity option(s) should I use?
You would typically use just one of the options at any one time. Use the "Triangles as polyface mesh" option to get an exact replica of the terrain. Use "Triangles as 3DFACE entities" for the same purpose if the program which will be importing the DXF file doesn't understand polyface meshes. Use "Square grid as polyface mesh" if you want to drape a regular grid on top of the terrain. The grid sometimes makes it easier to visualize the terrain, and it can often yield a much smaller file by reducing the polygon count. One major drawback of the square grid is that it misses many of the details of the terrain, such as road edges.
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Can I change the size of the grid squares?
Yes. You can make the grid finer by entering a different value in the Info Panel for the DTM. The place to do so is in the top right corner, "Max. grid squares." By default this is 1000, which would mean about 31 x 31 squares for a square data set. Just keep in mind that the larger you set this value, the longer it will take, both in SimuTerra as well as in the program which imports a DXF file if you export this square grid. If you change the value from 1000 to 4000, you will get grid squares which are half as wide.
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Why do I see triangles when I import a square grid into another program?
When you export the square grid, you are actually exporting triangles (or, more precisely, one polyface mesh which consists of triangles). Each square is really two isosceles right triangles joined along their respective hypotenuses (i.e. each square is split along its diagonal). The standard DXF flag is set for the common edge of each pair of triangles so that it will be hidden.
But that flag may not be respected by the importing program. And in SketchUp, where you can choose to hide and show edges, you can choose to show all the edges and you'll see them all, including the diagonals.
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Why does the DTM seem to be incorrectly scaled when I import it into another program?
This is probably an issue of units of measure. Before you import data into SimuTerra, you should typically set the units to those used in the file which you are importing. You can do this by choosing Doc > Units.... One notable exception is when the DXF file contains inches but they represent feet in the real world.
You should also indicate (to the program which is importing what SimuTerra exported) which units to expect. In SketchUp you can do this in the Import dialog box.
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Which version of SketchUp is compatible with SimuTerra.
You can import SimuTerra-generated DXF files into SketchUp 3.1 and later, and probably earlier as well.
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Why are the triangles which are imported into and displayed in SketchUp slightly different from those exported by SimuTerra?
SketchUp might ignore very tiny or thin triangles.
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Can one export Simuterra contours to a 2D CADD program to use as a basis for a grading plan?
You can export the contours from SimuTerra as 3D entities in a DXF file. Presumably your 2D CADD program can read the 3D contours and simply strip off the Z values.
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SAVING
Why is the Save menu item not enabled in the File menu?
On the Macintosh, the Save menu item should always be enabled. On the Windows version, it will only be enabled if there has been a change to the data in the document since the last time that the document was saved, opened, or created.
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What happens when I save a file?
All data and view information is written to the file. DTM parameters are also saved, though the DTMs themselves are not; they are recalculated when the file is opened again.
Furthermore, when you save, the Undo and Redo stacks are cleared, meaning that you won't be able to Undo or Redo anything which you did before saving (at least not by choosing from the Edit menu). Lastly, all objects which were flagged as being deleted will be permanently deleted.
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Why is the File > Save menu item enabled even though I've just saved?
This is becoming the standard in Mac OS X. The reasoning is that your document might change due to factors other than yourself, such as through an AppleScript. SimuTerra documents, however, cannot yet be affected by AppleScript.
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FILE AND DATA FORMATS
Are SimuTerra files cross-platform?
Yes. If you save a SimuTerra file (which has a suffix of smt) on a Macintosh, it can be opened by the Windows version, and vice versa.
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What can I do with data from a 2D CAD program?
You can change the elevations of points and polys once they are imported into SimuTerra, or you can do this inside another program. In SimuTerra, you can change the elevations either before or after creating a DTM.
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OBJECTS
What is a modifier?
A modifier is an object whose purpose is to alter the terrain. If a point or poly is not a modifier, and it is included as part of the data for creating a DTM, then it will be part of the calculation of the Existing DTM. If you make a point a modifier, or make a poly a modifier (either a road, pad, or collar), then it can be used for creating the Proposed DTM.
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What is a collar?
A collar is a closed poly which restricts the effect of enclosed modifiers. If a modifier is surrounded by a collar, then the effect of the modifier is extended out until the collar. You can create collars. There are also invisible, automatic collars which are created around roads and building pads.
Collars which overlap are automatically and invisibly merged into one collar; this is done during calculation of the DTM.
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Can object labels be displayed?
Yes. You can do this for one object at a time in the Info Panel. Or you can do this for multiple points, polys, or entels by choosing the appropriate item from the matching menu in the menu bar. In these dialogs, you need to click on an item until a black checkmark appears. You have to specify that you want a label to appear, and you also have to specify what you want to appear in the label.
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How do I know the elevation of an object?
There are a few ways, depending upon the object. For a point or poly, you can display a label which contains the Z value (the poly's Z value is meaningful only if the poly is horizontal). For a poly you can also have a label displayed for each vertex. You can also double-click on a point and see its elevation in the Info Panel.
You can use mouse tracking to see the elevation of the surface of a DTM at the mouse location. On the Macintosh, choose Window > Mouse Tracking; on Windows, look in the status bar at the bottom of the SimuTerra window.
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Can I edit elevations of objects?
Yes. With a dialog box, you can set the elevation, or indicate how much to raise or lower the elevation, of a single object or multiple objects. You can use the mouse to drag objects up and down. And you can use the mouse to click on objects so as to set or raise their elevations.
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Can I place objects on the surface?
Yes. This is called floating, and it works on points, polys, and entels. It will not work on a point or a poly which currently serves as data for a DTM. The objects are raised and/or lowered so as to be on the surface of a DTM which is present in the document.
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Can I duplicate objects?
Yes, even a DTM, as long as you are also duplicating its data at the same time.
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Can I copy/cut/paste objects?
No, none of this is possible yet in SimuTerra.
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Can I scale object coordinates?
Yes, in X, Y, and/or Z. You enter a coefficient for each of the three possible directions. For instance, you may want to double the Z values of all selected objects, in which case you would enter a value of 2. If you want to flip from positive to negative, enter -1.
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What is the snap feature?
When you drag a point, poly, or poly vertex, it can be made to snap to an unselected point or poly vertex. Snapping affects dragging only; it has no effect when clicking to create an object.
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POLYS
Can I edit individual vertices of a poly?
Yes, with the mouse. You have to first unlock the vertices of the poly, either with the Info Panel, or by selecting one or more polys and choosing Poly > Edit Polys.... And you have to aim well so that the tip of the arrow in the cursor is on the vertex.
You can use the Drag Tool (horizontal green double-headed arrow) from the Tool Palette to drag a vertex horizontally. You can use the Raise Tool (vertical green double-headed arrow) from the Tool Palette to drag a vertex vertically.
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Is there a way to individually adjust vertex points on a poly numerically, such as for a road?
Somewhat. There isn't yet any interface so that you can type in vertex coordinates, poly slope, etc.
But you can display a label for each vertex of a poly, and that label can contain X, Y, and/or Z coordinates. You can optionally open an additional 2D view in which you zoom in on the poly so that you can see the individual labels (choose Window > New Window). And these labels are updated in real time, so you can move a vertex until it reaches the desired position. (The updating is usually more responsive in the frontmost view.) Keep in mind that the larger the 2D view, the slower the reaction time, as there are more pixels to draw.
You can also mouse tracking to get a better idea of the X and Y coordinates. On the Macintosh, choose Window > Mouse Tracking; on Windows, look in the status bar at the bottom of the SimuTerra window (not the individual document window).
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Can I filter polys?
Yes. Often an imported poly will have many superfluous vertices. It has been found that typically 75% to 90% of vertices can be removed with very minimal impact on the appearance of the DTM. This leads to a similar reduction in the polygon count of DTMs created with these polys. An example of superfluous vertices is vertices along a straight line: you only need two endpoints to define a straight line.
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Can I join (merge, splice) polys?
Yes, if their ends match exactly. For instance, if you have three separate polys, each of which consists of one leg connecting two vertices, and they form a triangle, joining them will create one closed triangular poly consisting of three vertices.
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ENTELS
What is an entel?
The word entel is short for entourage element. Entourage is the content other than the terrain itself, such as people, cars, dogs, and trees. They can be animated.
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What purpose do entels serve?
They may help to visualize the terrain, and to entertain. You can tell entels to follow a specific poly, so you could have a bunch of cars driving along a road. Or you can have them go downhill.
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Can I create or import my own custom models to use as entels?
Yes. There is a folder named CustomEntels, inside of which are two folders: Models, and Textures. The model which you import must be a 3DS model, and its file must end with the suffix 3ds; this model goes into the Models folder. Any accompanying textures go into the Textures folder. Textures can be PNG, JPEG, etc.
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Can I import ready-made models from another source for use as entels?
Yes. For instance, you can get some from FormFonts (www.formfonts.com). But as of this writing, textures don't appear for these models.
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What kind of animation is there?
The built-in people, cars, and dogs can be animated in the sense of arms, legs, and tails moving, and all entels, regardless of source, can be animated in the sense of moving from one place to another.
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Can I resize or scale the entels?
Yes, you can scale them up or down to any extent. SimuTerra uses meters internally. So if you have a 3DS model which is based on inches, you will have to enter a scale factor of about 0.025 for your entel to be at the correct size. You don't have to be "correct" about the sizing; you may want dogs to be larger than cars, for instance.
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LAYERS
Does SimuTerra have layers?
Yes. You can import, add, rename, and delete layers. You can move objects between layers. You can set layers to be visible/invisible, and editable/uneditable. You can set any layer to be the target layer, so that any new object that you create will be in that layer.
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DTM
What is a TIN?
Triangulated Irregular Network. It is the result of triangulating all of the data which you supply. It is the underlying structure of a DTM.
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What is a DTM? A DTM set?
Digital Terrain Model. A DTM set consists of an Existing DTM, and can optionally consist of a Proposed DTM, and even a Cut & Fill DTM.
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How do I know if an object is part of a DTM?
To check whether an object is part of the DTM, you can try dragging it around, even outside of the hull of the DTM, and see if the DTM changes. Try also using the Raise Tool on the object; dragging up and down in the 2D view will cause the object to rise and fall. You can only drag data inside a 2D view, but sometimes it's easier to see the terrain change inside a 3D view. So you might benefit from having the two different views side by side.
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What do convex and concave refer to?
SimuTerra only does convex at this point; it creates a convex hull from the data. That means that the imaginary bounding polygon has no external angles which are smaller than 180 degrees. That's similar to placing a nail through every point and every poly vertex, then stretching a rubber band and placing it around all the nails. Some nails along the eastern edge, for instance, are just inside the rubber band, so you get many very slender triangles along the hull, and contour lines passing through those triangles. At some point SimuTerra should also do concave, meaning that it will "suck in" the rubber band.
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Why is there more than one menu item for creating a DTM?
For typical data you simply use Create DTM. But SketchUp foam core models have a lot of extraneous data in that almost every horizontal poly (edge, in SketchUp) has another one just above or below it. The custom menu items know how to ignore these unwanted polys. There are two methods for doing so, because there are different scenarios. Experimentation will teach best which one to use.
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Can SimuTerra show contour labels?
Yes. Once a DTM is created, you can turn them on and off in the Info Panel for the DTM. They only appear in 2D views, and are always horizontal. You can change the index multiple so as to affect how many of the contour lines are index contours (labels can only appear on index contours).
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Can I rotate contour labels?
No; they are always horizontal.
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Why is the DTM > Create DTM menu item disabled?
This item is enabled only when the program senses that enough objects are selected in order to create a DTM.
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Is there a limit to the size of the DTM?
There is no specific limit in terms of number of objects, but the more objects, the slower it will go. It is reasonable to handle tens of thousands of polys, or perhaps around one hundred thousand points, in this version (1.0.0).
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What is a breakline?
It typically refers to a poly which you use to force linear interpolation along its length (linear from one vertex to the next). It can be horizontal or sloped. Each imported contour line is in a sense a breakline. Triangle edges of the TIN typically do not cross a breakline.
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Can I use breaklines?
Yes, even after a DTM is created. You would create a poly to serve as a breakline, then choose Object > Add to DTM.
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How is SimuTerra different from using a topo-related Ruby script in SketchUp?
SimuTerra is written in C++, and is compiled so as to run very fast. Ruby scripts cannot be nearly as fast. For small data sets speed is not an issue, so a script may be preferable for triangulating, because it is right there inside of SketchUp. SimuTerra, however, has many more features that current Ruby scripts don't have.
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Can I create a DTM from a SketchUp foam core model?
Yes. But there are many different varieties of foam core models, and some may lead to calculation errors or undesirable results. There are different ways of creating a DTM from a foam core model; sometimes you will have to experiment.
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Why are there inconsistencies along the edge of a DTM created from a SketchUp foam core model?
There is extraneous data along the edges, and it is difficult for SimuTerra to know what to use and what to ignore. So some adjustment might be necessary.
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Why doesn't the DTM go all the way to the corner of the SketchUp foam core model?
If a contour line doesn't go to the corner, then there isn't a clear indication that the DTM should include the corner. You can, however, add a point at that corner in SimuTerra, raise it to (or assign it) the appropriate elevation, then choose Object > Add to DTM. The DTM will then go to the corner. You can do this for multiple corners.
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Can I see the square grid before I export it?
Yes. It does not need to be visible in order to export it, but it's helpful to get an idea of what it is that you will be exporting. In order to display the grid, open the Info Panel for the DTM, and click on the checkbox in the second row (Labels/Grid), under '3D', for the DTM for which you want it displayed (usually Existing DTM, or, if it exists, the Proposed DTM).
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Why doesn't the square grid cover all of the area of the DTM?
A square is created only if it is totally within the hull of the DTM.
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What if I want some data to NOT be part of a DTM?
Before you create a DTM, only select those points and polys which you want to be part of the DTM. Once a DTM is created, you can select those objects which you want to remove from the DTM and choose Object > Remove from DTM.
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Do imported contour lines have to be continuous or at regular intervals?
No. SimuTerra uses whatever bits of information you feed it.
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What's the difference between using points and using polys when creating a DTM?
Polys give additional information. The vertices of the polys serve the same purpose as points. But then SimuTerra forces the triangulation to follow the legs of the polys, causing linear interpolation along them. That means that the result will adhere to whatever contours and breaklines you feed it. This depends on some other factors as well; for instance, if you have polys which cross each other, then SimuTerra can't necessarily honor both crossing polys, as they may provide conflicting information.
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What is the purpose of the various DTM numerical parameters?
These items are covered more completely in the built-in help system, which is also available on our web site. These parameters include contour interval and various options as to what should be displayed, such as contour lines and triangles.
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Can I simplify the terrain (reduce polygon count)?
Yes. Doing so would make it a lot easier for other programs to import and manipulate the model.
One way is to filter out extraneous vertices from imported polys. (Sometimes the imported contours are strings of separate simple polys placed end to end; this is typically the case with DXF files exported by SketchUp. In this case, you should join the polys first.) By filtering out vertices you reduce the number of triangles needed to represent the terrain.
You could also export a square grid (really a triangulated regular network, or TRN) instead of the underlying triangulated irregular network (TIN). You can control roughly how many squares are in the TRN; you can often make it just a fraction of the number of triangles in the TIN.
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Can I create a DTM from 2D data?
Yes. All 2D data would be assigned an elevation of 0.0 when you import it. You can create a DTM from that, but it would be flat. You can change the elevations of the objects either before or after you create a DTM.
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What is a Cut & Fill DTM?
It is the third kind of DTM in a DTM set. Typically you start with data which represents the existing terrain; when you create a DTM from it, you have created an Existing DTM. If you also have design elements which are meant to modify the terrain, such as building pads and roads, then you can create a Proposed DTM as well. Once you've created a Proposed DTM, you can also create a Cut & Fill DTM which will represent the earthwork necessary to get from the Existing DTM to the Proposed DTM.
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Can SimuTerra show triangulation?
Yes, in both 2D and 3D views. You use the Info Panel to turn their display on and off. In the 3D view, when you see triangles, you normally see them filled and textured. You can turn off the filling by choosing View > Wireframe while the particular 3D window is active.
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Can I drape a texture or photo onto the model?
Not in SimuTerra. But if you export the model from SimuTerra and import it into SketchUp (and probably some other programs as well), then you can drape a texture or photo onto it.
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Can I make a swale?
Yes, in a couple of ways. One way is to create a building pad; a swale will be automatically created outside of the pad at a constant distance. Another is to draw an open poly along the bottom of the swale, and set it to be a modifier; then place a closed poly around the swale and set it to be a collar so as to represent the top of the slope.
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Can I make a building pad/slab?
Yes. You can draw a closed poly and set it to be a "Pad." You can optionally adjust its elevation, and you can also manipulate its individual vertices such as if you want there to be a slope.
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How should I deal with a building footprint or a building?
You can use the building footprint to guide you in creating a closed poly outside of it to act as a building pad. You would usually use various layers, so as not to confuse existing terrain data; design objects such as building pads and roads; and other miscellaneous points and polys which aren't meant to serve as data for a DTM.
If you have the building itself in SketchUp, you can export it via 3DS to serve as a custom entel which could then sit on the building pad in SimuTerra. The purpose would typically be to assist in the terrain design process; SimuTerra would do a better job of rendering. You may need to scale the size of the building once it's in a SimuTerra document.
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Can I make a parking lot?
Yes, a fairly basic one. Follow the instructions for making a building pad.
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How do I know the elevation at a particular location?
You can see the elevation of a DTM at a particular location by choosing Window > Mouse Tracking (Macintosh) or by looking in the status bar at the bottom of the SimuTerra window (Windows). You can also display labels for points, polys, and poly vertices; they will change in real time as you manipulate the data.
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Can I determine the slope at a particular location?
Not directly. You would have to look at elevations a known horizontal distance apart and do the arithmetic yourself.
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Can I have a hole in my contour map?
No, other than making an area horizontal (such as with a building pad) so that no contours pass through it.
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What do cut & fill volumes represent, and how are they calculated?
For an Existing DTM or a Proposed DTM, "cut" represents the cut necessary to get from the DTM surface to a horizontal plane at datum elevation (which you can set in the Info Panel). "Fill" represents the fill required to get to that plane. The net cut is the cut volume minus the fill volume.
For a Cut & Fill DTM, "cut" represents the cut necessary to get from the Existing DTM surface to the Proposed DTM surface, and "fill" represents the fill required to get from Existing to Proposed. The net cut is the cut minus the fill. If the net cut is zero, then the site is balanced, meaning that whatever is cut within the bounds of the DTM will be used as fill elsewhere in the DTM.
These volumes do not take bulking, compaction, surface stripping, etc. into account, nor does it differentiate between cut material and fill material. If you need to take into account special materials, such as for roads, you will have to calculate that separately.
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Can SimuTerra make "foam core" models or rather just meshes?
No, SimuTerra cannot (yet) make foam core models.
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ROADS
Can SimuTerra do roads?
Yes, in the Pro level you can do basic roads. A road is represented by an open poly, which runs along the center of the road. You can create a road by importing or creating a poly, and changing its parameters to meet your needs. The terrain is automatically cut or filled as needed. However, if the roads and building pads form a closed loop, the enclosed area may not appear as desired.
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Is it possible to color or texture a roadway?
Yes. You select a poly which represents a road, and in the Info Panel you specify a color and whether to draw the pavement in 3D views. There is one texture which is used for all roads.
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Can I extrude a cross-section along a road, such as for pavement and curbs?
Yes. You can see a wireframe version of the extrusion in SimuTerra; the full surfaces are included when you export the extrusion to a DXF file. See the road extrusion question in the Export section of the How-To guide for further information.
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Can I import a road?
Yes. But the road should be one polyline or equivalent in the DXF file, and should represent the centerline of the road. Once in SimuTerra, you will have to set the purpose of the poly to Road.
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Can I set the slope of a road?
Only indirectly, by manually raising or lowering each vertex and viewing the elevation of the vertex. You will have to do the arithmetic yourself.
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Can the sides of a roadway be at different elevations, i.e., can the road be superelevated?
No superelevation at this time.
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Can the width of a road vary, such as in a transitional section?
Not by using a poly as a road. But you could emulate a road transition, for instance, by creating a trapezoidal building pad. This isn't a perfect solution, but it might work well enough.
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VIEWS
Why would I want more than one view of the same document?
So that you can view in 3D and/or from multiple perspectives as you edit your data.
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Can I select data in a 3D window?
No, not with the mouse. But you can choose Edit > Select All while a 3D window is in front.
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Can I hide certain types of items in a view?
Yes, by choosing View > Show in View.... That allows you to hide objects of various sorts, including the axis lines, for whichever view is in front. You can use this dialog for changing each view independently. Unfortunately, these settings are not saved in the file.
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MISCELLANEOUS
Does the cursor ever change?
No, not in this version.
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What units of measure are available?
For linear measure: inches, feet, yards, millimeters, centimeters, and meters. For area and volume there are the square and cubic equivalents, respectively. For speed there are those same six units per second, as well as miles per hour and kilometers per hour. You can change units at any time while using SimuTerra.
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Why is the sound volume low on web site videos?
The movies were recorded with the internal microphone of a PowerBook G4. Try the Flash movies; they should be louder, and should play on your computer as well.
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Why is there more than one tool for selecting objects?
This makes it easier to select objects of a particular kind.
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How can I speed things up? (too many vertices on polys; smaller 2D window; fewer windows; turn off animation)
DTM calculation: Try to have less data. And try to reduce the number of vertices along polys. Sometimes contour lines are scanned in another program, yielding enormous numbers of vertices along polys. Some CAD programs may offer a way to filter out extraneous vertices, perhaps with a function name such as Simplify.
Views: Much of the time is spent drawing. The fewer windows that are open for a particular document, the less drawing will be required. 2D windows take longer to draw than 3D windows. In the case of 2D windows, the larger the window, the slower the drawing.
General: If there are entels in the document, turn off animation unless you want any entels to move.
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Can I do grading plans?
SimuTerra might be helpful in the creation of grading plans, but it doesn't do them by itself. For instance there is currently no way to display the slope at a particular location, or to set the slope.
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Any solution for surveying, coordinate geometry (COGO), deed plotting, and the like?
We have other programs which run on Mac OS 9 which may be of interest, but nothing for Windows or Mac OS X. Yet.
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What programs is SimuTerra compatible with?
SimuTerra has been tested with SketchUp, and works well with it. A bit of successful testing was performed with VectorWorks and PowerCADD. SimuTerra should work well with programs which can read or write the appropriate DXF entities, as described elsewhere in this document.
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Why does it sometimes take a long time to open a SimuTerra file containing a DTM?
The DTM is recalculated when the file is being opened, and a complex DTM takes that much more time to calculate.
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END OF FAQ
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