extruding edges in 3dsmax for lowpoly fur

noktek

Hi everyone, 1st post here.
Ive been modeling some sort of lazy wolf/lion lately, it defenatly needs some planes/alpha channels for the fur.

Ive never been working with planes/alphas but im quite sure its the way to go to achieve this kind of furry effect im talking about.

illbriefly describe my workflow so far: box modeling crappy wolf shape in 3dsm, adjusting muscles etc in mudbox, topogun lowpoly, (theoretically more mud sculpting).

At this point i imported in 3dsm and selected some contiguous edges with "Edit mesh", shift+dragged them out, scaling and adjusting etc etc all fine.
I then noticed that the verticles were not welded with the rest of my mesh. i proceeded with a "weld selected 0.1 radius" and i tought it helped. the problem is it all keeps breaking up again, upon exporting as obj, upon applying "edit poly" modifier, upon skinning/weighting, i dont know what to do anymore,

noktek

verticles=vertices
and my mate is quite sure its someway related to uv mapping..

Mark Dygert

Yeap, you can only weld open geometry to open geometry. You can't weld open to closed. It would create illegal geometry and cause all kinds of problems. Maya lets you do this and there is no end to the problems it causes.

When you extrude an edge in max you actually get two edges and three polys. Its the same as chamfering the edge with a really low threshold and extruding the poly and collapsing the farthest poly out.

You can see this by extruding an edge then selecting the original edge and moving it, there will be another edge.

If you delete the extra faces and weld, it will orphan the newly extruded edge leaving you with no way to attach the open poly to the closed mesh.


When you skin you'll need to make sure the weighting on the hair plane verts match the verts on the closed mesh.

This is all deliberate to keep you from creating bad geometry. Which is fine as soon as you know about it, you can then work around it.

Eric Chadwick

Edit Poly/Editable Poly do not support fins, which are non-manifold meshes. Edit Mesh/Editable Mesh however does support this. So that might be the problem. If you only work in Edit Mesh, you can weld and it should stay that way. But if you convert to Poly or you export/reimport the model, it'll probably be split again.

Trouble is, Edit Mesh generally sucks for modeling purposes (no loops/rings, etc.). I would recommend using a simple modifier stack (Editable Poly, Skin), and making the fins a separate element in your Editable Poly base. Then just make sure to weight the base vertices for the fins with the same weights as the main body vertices they're snapped to.

noktek

thanks for the tips, @vig i guess you're using edit poly in these pictures? i think i managed to understand now even thou its been 9hours im working on it.. tired..

so basically the best way to go would be edit mesh, shift extrude, select, detach to sep object, weld vertices on each of the two sep object, reattach together;

again, thanks for the comprehensive answers!

Mark Dygert

ahh yea I was using edit poly. I forget edit mesh exists most days =P

Eric Chadwick

If you use Editable Mesh, you don't have to detach/weld/reattach. Just shift-move the edges. You only need to detach if you want to use Editable Poly or Edit Poly.