triangle mesh with GImpact HOWTO

[teseien]

Hi, i wanto to use a triangle mesh made in blender in my bullet application, how do i must to do? i seached some tutorial but i can't find any page that explains how to set up a triangle mesh in my bullet world as a box shape or a sphere shape, so no static but dynamic object.

I read that dynamic objects made as triangle meshes are controlled by GImpact but in its site i can't find any information, it redirect to Bullet forum for more detail or information so i'm here XD

[sylvain.meunier]

Luckily, I'm working with GImpact. However I don't use dynamics and maybe it will lacks some wiring.

How to wire a collision object :

Code: Select all

  btIndexedMesh indexedMesh = {
    ... // Fill this structure with the object mesh data
  };

  btTriangleIndexVertexArray* indexedMeshes = new btTriangleIndexVertexArray();
  indexedMeshes->addIndexedMesh(
    indexedMesh
  );
  
  btGImpactConvexDecompositionShape* shape = new btGImpactConvexDecompositionShape(
    indexedMeshes, btVector3( 1.0, 1.0, 1.0 ) // Adjust this scale value
  );

  shape->setMargin( 0.0 ); // Adjust this margin value
  shape->updateBound();
  
  btCollisionObject* collisionObject = new btCollisionObject();
  collisionObject ->setCollisionShape( shape );

How to wire a collision world :

Code: Select all

  btDefaultCollisionConfiguration* configuration = new btDefaultCollisionConfiguration();
  
  btCollisionDispatcher* dispatcher = new btCollisionDispatcher( configuration );
  btGImpactCollisionAlgorithm::registerAlgorithm( dispatcher );

  btCollisionWorld* collisionWorld = new btCollisionWorld(
     dispatcher,
     new btDbvtBroadphase(),
     configuration
  );

  collisionWorld->addCollisionObject( ... );
  collisionWorld->addCollisionObject( ... );
  collisionWorld->addCollisionObject( ... );
  ...