Creating Holes in GeoMipTerrain?

Scripting Issues
#1

Hey everybody! Long time reader, first time poster. I’ve been reading these boards for so long, I feel like I’ve known some of the regulars for years. :smiley: I’m starting to get my hands dirty with terrain generation using Panda3D. I do have a question, however, regarding GeoMipTerrain.

Say I want to build a structure that goes “underground”, beneath the terrain object. I need to be able to select certain triangles and “turn them off”, so to speak. i.e. Not render them, and allow a player to pass through without colliding.

Has anyone else tackled this problem, and can anyone give me some pointers on how to pursue this with a GeoMipTerrain object?

Thanks a bunch!

#2

I use the AlphaTestAttrib for that sort of stuff:
panda3d.org/manual/index.php/Alpha_Testing
and have a texture where black means holes, and white means visible.

#3

Yeah, that’s pretty much the approach I was looking at, too. What scale alpha map do you use? The same as your heightmap? Or higher?

#4

Totally depends on how big your holes are and what shape exactly.
Usually, I don’t need that much detail, because I dont care if the hole isn’t exactly round - I make sure my ‘cave’ or so overlaps with part of the terrain.