SIMUTERRA PLUGIN FOR SKETCHUP

PURPOSE

To provide access within SketchUp to some of the functionality of SimuTerra.

REQUIREMENTS

Microsoft Windows
SketchUp 5
SimuTerra version 1.2.24 (licensed)

FEATURES

SimuTerra functionality supported (in SketchUp terminology):
* create terrain from edges and/or construction points
* create contours
* join and filter edges so as to simplify the resulting model
* create variable-sized square grid (typically to reduce polygon count)

INSTALLATION INSTRUCTIONS

* Download and install SimuTerra (version 1.2.24 or later) from www.compuneering.com
* If it didn't already get installed automatically, move this file (TerrainUsingSimuTerra.rb)
into the following folder (probably on your C drive):
Program Files\@Last Software\SketchUp 5\Plugins
* Contact COMPUneering for keys (any level of keys will allow access from within SketchUp)

USAGE INSTRUCTIONS

(Distance and elevation values should be entered in inches, at least through version 1.2.24 of SimuTerra.)
In SketchUp, select some data (groups, components, and their contents are ignored; only edges and construction points are used).
Choose Plugins > Terrain Using SimuTerra.
If you want to have a dialog box appear so as to control the various options, choose Plugins > Terrain Using SimuTerra With Options.
Creating just a terrain (triangles; equivalent to a sandbox), and/or a variable grid, is very quick.
Creating contours, and joining and filtering edges, are much more time consuming.
Some process information is displayed in the status bar, but there is no progress indicator.
If you choose to create contours, then you can allow the program to choose a contour interval, or you can specify one.
If you choose to join and filter edges, you should specify a filtering threshold;
this would typically be up to half of the distance between the two closest neighboring contours.
If you specify zero for the filtering threshold, then vertices along a straight line will be removed, as well as duplicates at the same XY location.
If you choose to create a variable grid, then you can specify three parameters to adjust the results.

OPTIONS

Create TIN triangles (Yes/No)
Create contours (Yes/No)
Specify contour interval
Join & filter (Yes/No)
Specify filter threshold
Create variable grid (Yes/No)
Specify variable grid maximum square width
Specify variable grid minimum square width
Specify variable grid elevation (z) tolerance (absolute value or percentage of elevation range)
Show statistics (Yes/No)

VARIABLE GRID TIPS

* If you are going to create a variable grid, then you will probably not want to create either TIN triangles or contours.
* If you specify the same size for both maximum and minimum square width, then the squares will all be uniform in size.
* You may want to start out making the maximum square width equal to about one quarter of the full east-west or north-south range,
and make the minimum about one tenth that range.
* If the results are too rough, then undo or delete what was created, select the original data, and try again,
specifying smaller squares and/or a smaller z tolerance.
* Squares are typically smaller around the perimeter, and the edge is usually rough.
* Each square is divided into two or more triangles, so that each face is guaranteed to be planar.
* For simple data sets, the final polygon count will probably be smaller with TIN triangles than with a variable grid.

RESULTS AND GROUPS

If triangles are created, then the terrain is placed inside a group.
If contours are created, then the contours are placed inside a group
If joining and filtering are chosen, then the edges will be joined and filtered inside of SimuTerra, used for creating the terrain,
but will not be sent back to SketchUp.
If a variable grid is created, then it is placed inside a group.