I’m trying to set up my scene for a still render. My model is clothed and the clothing uses cloth physics. Therefore, I would like a number of frames to “pass” before I perform the actual render.
How do I achieve this?
I watched a tutorial on something similar here, but it’s using an older version of Blender and I cannot find any Object/Scripts/Apply Deformation menu item in the 3D view of Blender 2.63a.
Can anyone explain the basic process involved in taking a still render of a scene that includes physics that must first be calculated?
Run the cloth simulation. Go to the frame that has the cloth looking as you want and then press the Apply button in the Cloth modifier that the cloth object has. This will fix the mesh the object has at that particular frame
Thanks for rescuing my sanity, Richard. I just wasted 3 hours trying to figure that out!
I hesitate to follow one question with another, but do you have any tips on using armature deformation in conjunction with cloth simulation? I have an armature, a body, and a top. Both the body and top are bound to the same armature, and both the body and top move with the armature. However, the body moves slightly more, so the clothing ends up being inside the body.
Not really. but matching the vertex weighting to get the top to move exactly the same as the body is more difficult than is practical. One way to work around this issue is to combine Armature deformation with Cloth simulation and use Cloth Collision to keep the cloth from penetrating the underlying mesh.
In order to use both Armature influence and Cloth sim influence on the same mesh, the vertex weighting for the two influences has to be balanced. Using weighting of the Cloth Pinning vertex group you can control how strong the cloth sim influences any portion of the Cloth mesh. If its Cloth Pinning weight is zero (or Pinning is not enabled), a vertex acts completely like cloth & is not influenced by anything else. By adding weight to the Pinning Group vertices, you reduce the Cloth sim influence and allow other influences like the Armature to have an effect. At Pinning weight = 1.0, the Cloth sim has no effect and the Armature can completely control a mesh’s deformation.
With Collision enabled, the Cloth mesh tends to penetrate the underlying mesh a lot less, but it isn’t perfect, especially with acute bends like at the knees and elbows. It helps in those cases to use the Mask modifier on the underlying mesh to make portions of the underlying mesh covered by the cloth non-rendering, so the penetrations don’t show.
@ridix: yeah, I had checked that. Both had exactly the same subdivide levels, although I’m not sure they had the same number of ngons. I tried increasing the subdivides on the clothing to give it more to work with, but that didn’t help either.
@chipmasque: thanks for explaining the process. It makes a lot of sense to me.
However, I wonder whether all I had to do was animate to my desired pose instead of switching straight to it with the pose library. That way, my cloth and collision physics would have been simulated throughout the pose change, possibly stopping the cloth from penetrating the body. I’ll try that today and report back. Regardless, in future attempts I will follow the technique you outlined more closely.
OK, I tried my idea of animating to the desired pose, and for some reason the cloth is now just falling through my body with no collision at all. I’ve double-checked my settings, re-baked a few times, but that hasn’t helped. If anyone has any ideas I’d love to hear them.
Probably the most common reason for Collision failing is that the Cloth mesh and its Collision object need to share a scene layer, so make sure that’s done. Next make sure that “Pinning” in the Cloth physics panel is enabled and your Pinning Group is specified – this will insure that any pinned vertices work properly. Make sure Cloth Collision is enabled. Sometimes people enable Collision physics on the Cloth object instead of on the Collision object, so make sure that didn’t get switched. The order of modifiers on the stack can have an effect also. In general it’s best to have the Cloth modifier follow (be placed below) the Armature modifier if both are used on your Cloth object. Modifiers like Mask and Subsurf should follow the Cloth modifier.
The Collision object (probably your body mesh or a proxy for it) should have its Collision modifier below the Armature modifier to insure that Armature deformations are calculated first.
If you can post a .blend it’s usually a lot easier to sort out than guesswork.
BTW, animating from a ref pose to your “beauty” pose is a good idea, but make sure you use enough frames in the sequence. The Cloth sim will calculate the acceleration of the cloth mesh vertices based on a standard 30fps frame rate and Gravity = 9.81m/sec. So if you use only a few frames to go from pose-to-pose, it will treat that as a very fast and vigorous motion and your Cloth with tend to react very strongly, often failing the collision altogether. You want enough frames for the Cloth to react smoothly, plus enough frames to let the Cloth settle into place after reaching your target pose. This can often require as many as 300 - 600 frames depending on the setup.
The density of both your Cloth mesh and your collision object will also affect how well collision works. Too few vertices and there will be more mesh breakthrough. Too many verts and the collision calcs will take too long. Finding the optimum mesh density is often a matter of trial and error.
