Blendshapes, research, uv-mapping and sculpting

The last few days have been quite rewarding. Mostly because I’ve been working with quite a few things I previously wasn’t all that familiar with. I have done some simple blendshapes before, but now I got a good chance to take it a bit further. For the facial blends, I decided to go all out and work entirely in Zbrush for this. Before I started out I began reading up on how to solve the problem with connecting and blending displacementmaps together with blendshapes. After som looking around a stumbeled upon a character TD named John Patrick who hade an awesome description on his site: http://canyourigit.com/correctiveDisplacements.php

Basically you create you blendshapes in zbrushm export a displacement for every blend + one for the base pose. You then build a small network in Mayas Hypershade to create a pipeline that takes out the difference between the base disp-map and the maps for the blends and then adds them on top of the first map. The blending is then linked to the blendshapes so that they work simoultaniously.

Sculpting the blends in Zbrush was very intuitive and a big advantage was to be able to create symmetrical shapes. These will later be split up in two halves in maya. I found the book “Stop Staring” by Jason Osipa to be extremely helpful, it basically tells you everything you need to know about modelling, rigging, skinning and blendshaping a face.

The layer feature in Zbrush becomes very handy when making blends. First and foremost you create a base layer to start out from and then a new layer for every new pose. You can then “tween” the layers using a slider to check out the blendshapes and se how they react to eachother.

I’m also done with the uv-mapping of Yesim, it all went quite smoothly and I decided to split her up into three maps, mostly to make sure the face got a map for itself since it will need to have quite a few maps to match the blendshapes. The rest of the skin then was then placed together with some other things one map, just to minimize the numbers of sss shaders i will need later on.

Currently I’m dealing with the corrective blendshapes for Yesims body. This is needed to fix some deformation issues that couldn’t be solved with skinning. This generally works really well, I’m using the Comet Pose Deformer script for maya that allows one to create blendshapes without having to duplicate geotry and hook it up manually. The only problem I’ve run into, and it is actually quite a large one, is that after creating a few blendshapes the calculating time for the script goes through the roof. Currently I’m stuck wating for 30 minutes for every blendshape I create. I will have to find a way to solve or work around this.

Apart from that, whats left now is blendshapes for Jean-Francois face, his uvs and corrective blends. Then I’ll just have to texture paint everything, bake my maps, set up the shaders in Maya, get the corrective displacements going for the blendshapes, create a backpack for Jean-Francois and make some eyes….

Too bad I really dont have time for more sculpting, it’s a lot of fun.

Time for a final burst to get everything done now!

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