View Full Version : Urgent: enveloping elbows, lattice deformation

08 August 2004, 09:48 PM
i have this little problem with enveloping
no matter how much i work on painting weights some joints ,ike elbow or knee, when it bends it loses its volume and gets thinner.

i am a former max user and in max there was lattices for morphing or deforming those areas according the angle between those two joints. so when it bends it moves the poins to the right positions nomatter how wrong your vertex weighting is.

my question is so how do we do that in XSI?
is there an equivalent to this gizmos or is there another workarond for ithis problem in xsi.

i know maya has lattices as well for deforming those areas but i have no idea to corrcet this thing in xsi.

08 August 2004, 10:18 PM
Concept is the same. Select your points, get a lattice, then link parameters to move points.

08 August 2004, 10:51 PM
i dont getit. canyou be more specific. iamvery new to xsi?
howdoi link parameters ?

08 August 2004, 11:13 PM
Actually I don't think you can use a lattice with link parameters. The way I would solve your problem is by creating a grid, lets say 4x4. Take that grid and move it to the elbow area. Go into point mode, click all the points and then create a cluster. Then take the grid and use a shrink rap deformer and use the follow vertex normal option. That will take your grid and try to mold it around the elbow area. You can move it around and scale it, etc. Move points to make it look just like you want it. Then freeze the grid. Now get a script called add points to null from netview. Click the grid and run the script and use the null to point. What this does is create a null on each point, also the points control where the null is. Now take the grid and envelope it to the arm bones. Goto deform, link with orientation. Now goto deform, save shape key. Next move your arm in a flex position. Then grab the grids points and shape them like you want and hit save shape key again. Now when you flex the arm it should move the points for you. This might not be the best way to do it but its the only way I know how to, maybe a real rigger will come along and give you better options.

08 August 2004, 07:18 AM
Hello! I just found out how to do this in XSI and it's a breeze! Just switch to 'Secondary Shape Modeling Construction Mode' and move points (hit 'm') to correct position. After you done, select Deform > Shape > Save Shape Key and name it 'Elbow Fix' or something and you're done. No need to use lattice or anything. Now, if you open Animation Mixer there's track and slider for that shape key.


08 August 2004, 11:32 AM
thanks a lot for your answers guys.

ssalo: yeah it looksreally easy but i am also looking for a way to link it(like parameter wiring) to the angle between the bones upper arm and fore arm so it automaticly adjusts its weight.

any helpon this?

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