### Creation of a Scene (8/9)

Description

In this step of the tutorial we will change the collision model from the cube object to the dragon object, so that the collision model is using the same model as the visual one.

In the properties of the CollisionNode, change the Filename of the mesh from /Sofa/share/mesh/cube.onj to /Sofa/share/mesh/dragon.obj. In the properties of the CollisionNode's MechanicalObject, under Transformation, change the Scale of the DOFs in 3 dimensions from (6 6 6) to (1 1 1).
Results

Run in SOFA. Change the DT to 0.005. Animate.

You can see that there are many more sphere to handle the collision. Some are redundant, and useless.

This example demonstrated the need to carefully choose the collision model you want to use. A good approach is to have two versions of your model: a fine version used to do the rendering of the scene, and a much coarser one to handle the collisions quickly.

The presence of spheres may create some artifacts during the collision response, but they are very fast to simulate. Disable the display of the collision models and activate the visual models to really see the efficiency of the spheres.

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