[Bullet] Irrlicht Terrain Mesh to Bullet Mesh

[Nadro]

Hi, I have question about converting mesh generated from heightmap to Bullet btTriangleMesh. My current mesh converter don't work with terrain meshes. I get mesh in follow steps:
1. I generate ITerrainSceneNode.
2. I copy terrain LOD Buffer to CDynamicMeshBuffer.
3. I convert MeshBuffer to btTriangleMesh.

This is differences between 'collision' and 'drawing' meshes:






Collision mesh look as mix between Convex Hull and BVH... I have similar results when I use btTriangleIndexVertexArray instead btTriangleMesh

[BlindSide]

Have you looked at the bullet height field primitive? It is designed specifically for terrain.

Look at "btHeightfieldTerrainShape.h" in the bullet sdk under src\BulletCollision\CollisionShapes.

[Nadro]

No, currently I don't test btHeightfieldTerrainShape, because two independent create meshes first via Irrlicht and second via Bullet can return differences results eg. more smoothly etc... so I think BVH is better solution for it. I think problem is in Irrlicht terrain mesh structure, so converter can't rewrite it properly.

[dlangdev]

The Terrain Scene Node has no index that is required in Bullet. You can create the terrain in Bullet first and then pass it to Terrain Scene Node afterwards.

[Nadro]

Thanks for interesting of my problem, but I solved my problem.

[m506]

would you mind telling us what you did? I have similar problems.

Thanks

[Nadro]

In currently Irrlicht version indices are storage in irr::u32, so in Your Irrlicht to Bullet mesh converter You also have to change irr::u16 to irr::u32 eg.

Code: Select all

irr::u16* mb_indices = mb->getIndices();

to

Code: Select all

irr::u32* mb_indices = (irr::u32*)mb->getIndices();

Now all will be ok

[bitplane]

In currently Irrlicht version indices are storage in irr::u32, so in Your Irrlicht to Bullet mesh converter You also have to change irr::u16 to irr::u32 eg.

Code: Select all

irr::u16* mb_indices = mb->getIndices();

to

Code: Select all

irr::u32* mb_indices = (irr::u32*)mb->getIndices();

Now all will be ok

You should check the index type first with getIndexType()