Creating Collision Hulls for Terrain in Blender


Hi All! Just popping in to share a brief video we put together covering a pretty simple way to make convex collision hulls that work very well for terrain meshes in High Fidelity. Check it out and let us know your thoughts & questions. Thanks!


Yes, i forgot the collision shapes need to be seperate. First try failed. but have some other network problems i need to hunt tomorrow. Video looks good !


Neat video did you record this in high definition It would be better to see as you tube is not showing it HD


This looks good. And nice video tut.

I have not tried this out, so I know not what I am about to type.

Only thing I might add is: I would try decimating the mesh again before exporting the collision hull. Only because it seems to be a much bigger drain on performance than the visual mesh itself.

I think that any imperfections in the collision hull will be less noticable than the rendered object itself, so …etc… anyway… I guess I should test this out before making comments


You’re welcome

nice when the devs catch up to me and call it their idea lol
what would be nice would be if we could collide with an fbx, then we could keep the model size down.


Quicker way is to use all modifiers, its removes the chance of incorrect normals when extruding, and you can control the thickness. :

So in order:

  1. Decimate
  2. Edge Split
  3. Solidify
  4. Apply all Modifiers,
  5. Separate by lose parts



Still preffer a noirmal terrain we can paint nice and have good blends and can dig into. Mesh terrain is a pain already.

Made a terrain, but that is made out of one mesh, also the hills. And seperate by lose parts is not workinf good then. SO i have no collision hull but still square box. :frowning:


Thanks Menithal, this is a good sequence. I might add that you would probably want to export your FBX (visible mesh) before you solidify but after you decimate in order to keep the poly count low (1/6th) on it but still have it be the same surface topology as the OBJ collision hull.


Haha Judas, I’m sorry I didn’t see your earlier post. Oh well, it’s all in the interest of shared collaboration. For my part, I make no claim to owning the idea, it just seemed like a great alternative to using VHACD that was worth sharing.


Wasn’t claiming to own it just at the time no one else had done it and when I posted my method I was told it was " a bad idea" If I wanted to keep it secret I wouldn’t have posted in the forum :smile:)
That said I did say shhhhh its secret at the time :stuck_out_tongue:


I did use your technique, I made a thickness of 1.25 extrusion which will not have been enough as I go straight trough the terrain at high speed.

The avatar feet were floating above the surface, I did fix this by increasing the size of my avatar. My avatar his feet were also floating above the surface in sandbox so that is no the fault of your technique.

The biggest flaw is the avatar does not properly walk on the terrain, it drags its feet over the surface unless you are at the highest point of the terrain.

The avatar also just slides from a hill downward like it is doing winter sports.

Also making it so that the camera does not go through a compound shape is a must I think. You do not get a realistic impression when you walk on terrain when the camera goes through, the same for walls and objects that have a compound shape.