I am using bullet/ammo.js with three.js. I have a 3d mesh and I want to use the exact shape for collision detection with a soft body. Is there a way I can create a 3d rigid body (in bullet) from a mesh (in three.js)?
Here is an example: http://kidzinski.com/miamisura/lazy3d/ (please wait a second for the 3d model to download). I have a cloth falling on a 3d body and I need to simulate collision of this cloth with the body.
I am new to these frameworks sorry if I fundamentally misunderstood something.
It looks like you can do some work to turn an arbitrary Three.js mesh into a Bullet concave mesh. This is supported by Physi.js, which is a plug and play solution to link Three.js directly to ammo.js. I personally wouldn't recommend using the project (Physi.js) but you can look at the source code to see how they implement concave meshes.
First they loop over the geometry to create a custom list of "triangle" data objects on these lines of physi.js
for ( i = 0; i < geometry.faces.length; i++ ) {
face = geometry.faces[i];
if ( face instanceof THREE.Face3) {
triangles.push([
...
Then these triangles are passed off to Ammo.js to make a new Ammo.btBvhTriangleMeshShape
on these lines:
for ( i = 0; i < description.triangles.length; i++ ) {
...
triangle_mesh.addTriangle( _vec3_1, _vec3_2, _vec3_3, true );
}
...
shape = new Ammo.btBvhTriangleMeshShape( triangle_mesh, true, true );
This should be a good starting point for building your own Ammo.js custom mesh.