We present a simplified approach for the animation of geometrically complex deformable objects represented by tetrahedral meshes. Our prototype system detects and responds to collisions of objects that are subject to elastic deformations of variable stiffness. The proposed approach combines several techniques, namely, collision detection using spatial hashing, collision response with consistent penetration depth obtained by propagation, estimated displacement vectors for the deformation region, and binary search to separate objects. The dynamics is based on shape-matching and a modal analysis scheme, using an Euler explicit-implicit integrator. Preliminary results show that collisions between objects containing several hundreds tetrahedra can be animated in real time.