Mesh Deformer 0.3x Limits

I like tight clothes. I think they look sexy on either gender. So, when making mesh clothes I like to make them tight. Of course when making them for myself based on my custom shape, getting things to fit right is not much a problem. Then there is the coming Mesh Deformer. If I want to use the Mesh Deformer to make my clothes fit should I decide to change my shape or sell them to others, then I need to use the Default Shape as my modeling base.

My Skirt Beginning

Problem

The current version of Deformer in the Deformer Project Viewer is 0.3x. A new version is in development. We’ve heard a few things about the coming 0.4 version. Hopefully it will fix some issues I am running into. But, the Alternate Deformer may be a better solution. We won’t know for some time.

At some point we will be comparing the 0.4 Mesh Deformer and the Alternate Deformer. So, I want to start getting my comparison information together. In doing that I’ll document a problem I’ve run into.

Criteria

The first step is, of course, creating a skirt I want. The images here show a skirt in Blender 2.63a with a stand pose I have in my AO. I like my stands so my skirt needs to work with them. I also want this skirt to be boy-bait, which means this skirt should also work when I sit down.

When you try a demo in a shop, be sure you test it in with the poses you often use. Sitting is a common pose. There are problems with sit poses; at least they are problems for mesh clothes makers.

You may not have noticed that a female default sit pose moves the feet to the avatar’s left. This is done by slightly rotating the thighs in a counter-clockwise (looking at avatar) direction with the right leg being rotated slightly more than the left.

This creates a bump in the front of mesh skirts when sitting. See the image.

Problem with Default Sit Pose

This ‘bump during sit’ is nearly impossible to fix and have the skirt work right while walking. This is just part of limitations in how systems use animation and weight painting information. Until someone builds a better way to animate clothes, we’ll live with these types of problems.

Making it Fit

In building the dress I needed to figure out how much space to put between the dress and the avatar skin. The closer the dress the more difficult it is to deform it well as the avatar animates. The more space between the two the easier it is to weight paint and have it work. More space mean more room for error.

This is the skirt I want. I took this image while testing it for a leg forward pose I have in my AO. In case a fashionesta is reading this: !mPS! Juicy Stand1 by Tatyana Ultsch.

My pose in Blender is not an exact copy of the pose. I just got it close enough for weight paint testing.

The dress is incomplete. Here I am building and testing just the outer shell or surface of the dress. When I have the mesh shaped, positioned, and weight painted I can move on to adding the inside and UVMapping for the texture.

Here I have changed the view in Blender to show the spacing I used between the skirt and the avatar skin. Near the waist I probably have the skirt too close for the Deformer to correctly deform the skirt mesh. At least in version 0.3x.

My hope is the version 0.4 that is likely going to use the normals as well as position for finding the closest avatar vertex to a skirt vertex will improve the final result.

Currently the final result on an avatar using the Defulat shape looks like image DefProb04. The result is pretty much what I expected. There is some poke through. I can tweak that or hide it with an alpha layer.

 

In Blender 2.63a Showing Space Between Skirt and Avatar

The disappointing problem is the fit when I change to my custom shape. My hope is the Deformer will adjust the skirt to my shape. It adjusts it but sadly fails. See image DefProb05 . Karl Stiefvater has mentioned the problem in one of MetaReality’s podcasts, I think that is where I heard it. So, my hope is version 0.4 does a better job.

Skirt w/Default Shape – DefProb04

At first I thought the deformer was not working or I had forgotten to check the ‘Use Deform’ button. So, I did tests.

In image DefProb07 I have changed my shape to use maximum hip width 100. You can see the skirt is deforming with my shape.

Same Skirt w/My Custom Shape – DefProb05

As a secondary test I made my butt really big. You don’t get to see that. (That is a valuable consideration. You should probably send money.) My big butt works much the same between the Default Shape and my custom shape.

I think there can be no doubt there is a limit to how close we can place a skirt to the avatar skin and expect to have it work. My hope is the Deformer version 0.4 will let us get closer.

Skirt w/Hips Max’d to Show Deformer Working – DefProb07

I think the fix for this skirt at this point is to increase the distance between the skirt and avatar near my belt line. I have some other things to do before I can try that experiment.

Layers

Some designers want to have mesh clothes layering built into the deformer. That is definitely not in Karl’s scope of work. It is also something that designers can do on their own. They are going to have to be talented in model design, animation and weighting to make it work. Whether it is added to Karl’s deformer or not, mesh clothes layering is going to be complex for designers.

In most 3D virtual worlds the avatar mesh is taken out of the inside of the clothes. That reduce poly count and stops poke through. In Second Life we tough it out and render the polys. If we have to hide something we use an alpha layer. I’m not sure if the alpha layer takes those polys out of the render pipeline or not. I would bet it doesn’t.

Summary

I am looking forward to learning more about Redpoly’s C-Bones alternative to the Deformer and seeing version 0.4 of the Deformer in a new project viewer.

2 thoughts on “Mesh Deformer 0.3x Limits

  1. Pingback: MetaReality #SL Mesh Deformer plus Cloud Party

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