View Full Version : Bullet Cloth: Best Practices

02-24-2013, 02:45 PM
I'm new to cloth sim. My first attempt with Bullet Dynamic Bodies results in some nice effects. However, being new, I don't know what the industry "standard" practice is in terms of cloth object modeling and optimization.

Is it better to model cloth without thickness (single surface mesh with material set to double sided) or with thickness, an air gap between the outside and inside meshes?

I initially created my cloth objects without thickness for easy of modeling, then I applied Thicken to get a true outside and inside surface. However, this significantly increases calculation times due to the need for self-collision (so the two sides don't interpenetrate), etc.

The other thing is, once I was happy with how my first layer of clothing was simulating, adding the next layer on top of it resulted in a total soup of scattering polys in all directions for both meshes when I simulated again. Thus, I assume once one layer is finalized, you would then need to bake it to MDD, then change it from a dynamic body to a static body in Bullet so that the second layer can collide properly. That is, the first layer uses the character's body as the static or kinematic body for collision, then the second cloth layer would use the first layer changed to static instead of using the character's body to drive its collision, yes?

Is it better to use sub-division level of 0 or desired render level for Bullet (sub-D order set to last, for all bullet obj. or just those set as dynamic/soft bodies?)?

02-24-2013, 08:15 PM
I'm new to this as well, but I have had some practice with cloth simulation. For me, more polygons equals better dynamics. I just use a flat piece of geometry for my cloth...