Friday, December 04, 2009

MeshTool, Water and Land Class

MeshTool 2.0 is still a very new tool, so it shouldn't be surprising that it has grown quite a few features during beta. I am putting three new features in for beta 4 that should help round out the kinds of things an author can put into a mesh.

Land Class Terrain

The next beta will allow authors to specify built-in land-class terrains by shapefile. Landclass isn't quite as easy to work with as you might think - I'm working on a Wiki page describing how land class works with the mesh.

You can't invent your own land classes directly in MeshTool, but there are two work-arounds:
  1. Once you build your DSF, use DSF2Text to edit the header, changing one of our land classes to the one you want. We have 500 + land classes, so you can probably find one to cannibalize.
  2. Or you can just use the library system to replace the art assets for the land class within the area covered by your mesh. (You can tweak as little as one full tile.)
Water Handling and Masking

Water handling and masking go together to allow you to create an accurate physical coastline. The problem is that X-Plane doesn't let you specify whether a tile is land or water using a texture/image file. Physics are always determined on a per-triangle basis.

MeshTool 2.0 beta 4 will let you specify whether the physics of an orthophoto that has water "under" its transparent areas will take on its own physics, or the physics of the underlying water. (It can act "solid" or "wet".) This lets you use orthophotos to model shallow areas and reefs.

The mask feature lets you do both. The mask feature lets you limit MeshTool to working on a single area vector area, defined by a ShapeFile. So to make a single orthophoto have wet and solid parts you:
  1. Issue the orthophoto command in solid mode.
  2. Establish a shapefile mask for areas of your DSF.
  3. Re-issue the orthophoto in "wet" mode.
The second orthophoto command will replace the first only in the wet areas, giving you regions with both types of physics. The README for MeshTool will cover this in more detail.

No Z Yet

Some developers have requested that MeshTool use the Z coordinate in a Shapefile to define the elevation of water boundaries. That's a good idea, but I can't code it any time soon. The polygon processing in MeshTool is fundamentally 2-d and has no way to retain the Z information during processing. I will try to get to this feature some day, but for now it's going to have to wait.

The new beta should be available some time early next week, or now if you build from source.

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