No collisions when loading a softbody from an stl file

[lunaticstraydog]

Hello,
I've been trying to load a soft body from an stl file for a while now, and while it seems to load fine, it never collides with other bodies, be it soft or rigid ones.
I'm loading the stl file as follows:

stl loading code

	GLInstanceGraphicsShape* glmesh = 0;
	b3BulletDefaultFileIO fileIO;
	glmesh = LoadMeshFromSTL(name.c_str(),&fileIO);
	btAlignedObjectArray<btScalar> vertices;
	btAlignedObjectArray<int> triangles;
	for (int j=0;j<glmesh->m_numvertices ;j+=1) 
	{
		vertices.push_back(glmesh->m_vertices->at(j).xyzw[0]);
		vertices.push_back(glmesh->m_vertices->at(j).xyzw[1]);
		vertices.push_back(glmesh->m_vertices->at(j).xyzw[2]);
	}
	for (int i=0;i<glmesh->m_numIndices;i++)
	{
		triangles.push_back(glmesh->m_indices->at(i));
	}
	btSoftBody* psb=btSoftBodyHelpers::CreateFromTriMesh(getDeformableDynamicsWorld()->getWorldInfo(),&vertices[0],&triangles[0],triangles.size()/3);

Among the different approaches to the problem, I've tried :

• meshing the file more densely (only increases calculation time)
• generating collision clusters, which seem not to make any difference
• using options such as psb->m_cfg.collisions += btSoftBody::fCollision::VF_SS;, basing myself on the bunny mesh example, but that did not make a difference either (and I do not know what that option really does)
  Here is the full loading function

Full function

void DeformableMultibody::createSoftBodyFromStl(const std::string name,btVector3 origin,btQuaternion rotation,btVector3 scale,bool base_fixed)
{
		GLInstanceGraphicsShape* glmesh = 0;
	b3BulletDefaultFileIO fileIO;
	glmesh = LoadMeshFromSTL(name.c_str(),&fileIO);
	std::cout << "nombre de vertex : "<< glmesh->m_numIndices << std::endl;
	btAlignedObjectArray<btScalar> vertices;
	btAlignedObjectArray<int> triangles;
	for (int j=0;j<glmesh->m_numvertices ;j+=1) //full bidouille  et en plus c'est un coup a se planter ça
	{
		vertices.push_back(glmesh->m_vertices->at(j).xyzw[0]);
		vertices.push_back(glmesh->m_vertices->at(j).xyzw[1]);
		vertices.push_back(glmesh->m_vertices->at(j).xyzw[2]);
	}
	for (int i=0;i<glmesh->m_numIndices;i++)
	{
		triangles.push_back(glmesh->m_indices->at(i));
	}
	btSoftBody*  psb=btSoftBodyHelpers::CreateFromTriMesh(getDeformableDynamicsWorld()->getWorldInfo(),&vertices[0],&triangles[0],triangles.size()/3);
	btTransform trs;
	trs.setIdentity();
	trs.setOrigin(origin);
	trs.setRotation(rotation);
	psb->transform(trs);
	psb->scale(scale);
	btSoftBody::Material* pm = psb->appendMaterial();
	pm->m_flags -= btSoftBody::fMaterial::DebugDraw;
	psb->generateBendingConstraints(2,pm);
	psb->m_cfg.piterations = 2;
	psb->setTotalMass(1, true);
	psb->m_materials[0]->m_kLST = 0.1;
	//création de clusters pour assurer une bonne collision
	int numSubdivisions=10000;
	psb->generateClusters(numSubdivisions);
	psb->m_cfg.collisions += btSoftBody::fCollision::CL_RS;
	psb->m_cfg.collisions += btSoftBody::fCollision::CL_SS;
	// Options that do not make a difference
	/*
	psb->m_cfg.collisions += btSoftBody::fCollision::VF_SS;
	//psb->m_cfg.collisions = btSoftBody::fCollision::SDF_RD; //this one hangs indefinitly
	psb->m_cfg.collisions |= btSoftBody::fCollision::SDF_RDN;
	psb->m_cfg.collisions |= btSoftBody::fCollision::SDF_RDF;
	psb->m_cfg.collisions |= btSoftBody::fCollision::VF_DD;
	*/
	btDeformableGravityForce* gravity_force =  new btDeformableGravityForce(getDeformableDynamicsWorld()->getWorldInfo().m_gravity);
	getDeformableDynamicsWorld()->addForce(psb, gravity_force);
	m_forces.push_back(gravity_force);
	/*
	psb->m_cfg.kLF = 0.004;
	psb->m_cfg.kDG = 0.0003;
	*/
	getDeformableDynamicsWorld()->addSoftBody(psb);
}

I'm attaching the entire project with compiling instructions in the readme.
STL_loading.zip