effect of mask modifier on cloth/collision

Support Animation and Rigging
1

hello,
does anyone know is the mask modifier purely visual or does it affect whether an object is detected for collision? I assume its position in the modifier stack controls this but wasn’t quite sure.

also when using armatures to deform clothes and characters, where in the modifier stack do you put the collision and cloth? Is the armature always placed before the cloth and/or collision?

My objects are both on the same layer, but wherever I put the modifiers in the stack they still seem to fall straight through the objects. What number do I need to increase - is it min distance? All the cloth documentation I can find seems to be hugely out of date and doesn’t really cover much more than making another bog standard youtube “test”!

many thanks in advance

2

This is an old topic, but I would be glad to know if anyone knows the answer to this.

1 Like
3

This question is also relevant to my interests.
Basically tried this setup but the cloth simulation keeps breaking:
From the top down…

  1. Dynamic paint modifies the vertex group weights as a brush moves over it. (Works perfect)
  2. Mask modifier removes the faces based on the weight painted from #1. (Works very well)
  3. Cloth simulation works nice until the Mask modifier starts removing faces.
    At the point where cloth stops working two different things could occur:
  • When stepping through the frames manually it seems to reset the mesh shape on every frame
  • When baking the effect, well, all the verts gone haywire all over the place.

I can reverse the Mask and Cloth modifiers but that defeats the point. Which I believe is to have the mask affect the cloth behaviour.

1 Like
4

I’d say, why not test? But from what you’re saying, sure sounds like the mask is affecting the cloth. In which case, since the main reason people use a mask modifier to hide parts of their mesh, why not do that in the material instead?

But you say the point is to have the mask affect the cloth behavior. Which it is, just not in the way you expected it to. So how is it you want the cloth to behave?

5

I’ve gone and made a simple test scene and I’ve realized that this is either a bug or more probably just not possible with the tooling provided. The mask does affect the cloth when static but it’s glitching out when animated.
Here is an example of what happens with what I was trying to do: https://imgur.com/a/zDeI2H0

6

I don’t think I’d consider that a bug. The mask modifier causes the topology to change-- the model, post mask, has a different vertex count than pre-mask. That probably means that vertex indices change, and vertices don’t know what their velocities should be from the physics. You’ll see the same behavior with any number of generative modifiers (try a build modifier.)

But again, the real question is what effect where you trying to achieve. Using a pre-cloth generative modifier, that acts dynamically, doesn’t seem like it makes any sense to me, but you must have had some goal in mind when you did it, and that goal might be achievable in some other way.

8

I understand now regarding the topology change happening. I suspectd that may be what’s causing the glitching.
The effect I was trying to achieve was basically part of cloth object disappearing over time and the physics would likewise change as if the cloth becomes smaller and smaller. It’s a novelty really, I’m just messing around and learning all the way.

9

What I’d recommend trying is using two different cloth meshes, animating render visibility, animating a surface deform influence, and animating a pinning group via a vertex weight edit modifier. So you’re basically making a different piece of cloth, locked to the full piece by surface deform and pinning, up until the point that you tell it to swap visibility and start going its own way :slight_smile: