Legacy Reference

Creating Joint Mesh Proxies

To help define body masses for character physics and collisions, you need to use a joint mesh proxy. To create a joint proxy mesh, observe the following guidelines:

  • Model meshes around the geometry that needs to be detectable. Meshes with lower polygon counts perform better.

  • Create meshes that use a generalized area instead of getting too granular with a physics mesh per joint to help with performance. For example, you could simplify a biped chest physics mesh proxy to cover the area of multiple spine joints instead of a proxy for each spine joint.

  • Nest a proxy mesh under its corresponding joints. The proxies can then be exported with the .chr (skeleton) files.

  • Proxy mesh naming must match the name of the joint it gets nested under with the addition of the following suffix:

    • For Maya, add the _Phys suffix (not case sensitive)

    • For 3ds Max, add the Phys suffix (not case sensitive)

  • To designate meshes as proxies, assign a material to them and changing the material type to Proxy No Draw. As a best practice, keep your ragdoll physics mesh materials in a separate material group.

In the following figure, two different proxy materials are applied to the proxy mesh. Lumberyard uses the different materials to detect different parts of the body. In this case, the separate head material allows the engine to distinguish if the head is interacting with an object, as opposed to the rest of the body interacting with an object. For example, if a character gets hit in the head, you might want a special animation reaction to play, as opposed to the character getting hit in the body.

Ragdoll characters can have more proxy materials to define specific areas of the body. For example, you can have a proxy material for the head, spine, hip, left arm, right arm, left leg, right leg, left foot, and right foot.