What am I doing wrong? [Blender/Avastar/3DsMax]

[Zakiel Windlow]

Hi! Well, for almost 1 week I've been facing this problem and I'm reaching the point where I want to give up; really, I don't know what to do. Probably it's a silly thing that I cannot figure out.

Problem:
On SOME models (.OBJ) imported from 3DS Max:
1) During Weight Paint, X-Mirror is not working
2) Weights are not applied symmetrically
3) Weights are applied symmetrically but X-Mirror doesn't work.
4) X-Mirror not working in "double sided" meshes, but do work whenI delete the inner geometry.

Context and details:
This is my workflow: ZBrush <> 3DsMax > Blender.

I've decided to learn Blender just to try out the rigging/skinning tools (like Avastar) and, in the process, learn the other functions and tools that Blender offer. All was going fine, until I tried to import my second object to Blender from 3DSMax, when I started to get the problems listed before.

What I've tried so far:
From 3DS Max:
1) Exporting as .fbx/.dae: X-Mirror works but I get a model composed of triangles. This becomes a problem when I try to edit it in Blender.
2) Exporting as any other format supported by Blender: X-Mirror doesn't work.

I've "played" with the export/import options in 3DS Max and Blender for the .OBJ, but can't find out the correct setup (if this is the cause). Really dunno what to do or what I'm doing wrong.

Here some screenshots:
1) These are my settings for export/import.


2) This image is from 3DS Max and is here so you can see the local axis and the global axis (lower left corner).
(This was the first mesh imported in Blender. The inner geometry was deleted.)
3) Imported in Blender. Did some weight paint with X-Mirror and is working
(Note the the weights are not symmetrical, dunno why...)


4) Second mesh: Image from 3DS Max son you can see both axis (again): Local and global.
5) Once imported in Blender, X-Mirror is not working. Its inner geometry is still there.


6) Just for test purposes: In Blender, I deleted the inner geometry and the little piece of the back. You can see that X-Mirror seems to be working now.


7) This is my "test box": You can see that X-Mirror is not working again.


8) Second test: Deleted the top and bottom faces, making a hole. Not working either.


9) 3rd test with the "test box": Did the UVMapping just to discard "one more thing" and nothing, you know the result.

Help? Any ideas?
Is actually the inner geometry the cause of the problem?
But how that explains, then, the results on my test box?
I'm ok with deleting the inner faces but need to know for future reference if I need a double sided mesh. I know I can use solidify and copy weights, but that would mean that Blender can't handle double sided meshes? And again: My test box is not double sided and X-Mirror is not working :matte-motes-dont-cry:

Thanks in advance.

[Astrid Kaufmat]

That's a good puzzle. Unfortnately I use maya not max. However I've been helping some friend with transferring meshes from one program to another and when I tested their fbx files in blender I had some messy results as well.

For sure I can tell you fbx would always be an iussue for blender, because several programs have an fbx eporter not compatible with blender.

I also doubt that Blender community could ever fix it, because all the paid rich programs wouldn't lose some rights.

Did you also try to export as obj  (just simple mesh object) to blender then save the scene as blend file and then close blender and open it again loading that scene? Then rig it in blender from zero.

This is the only suggestion that is coming in my mind.

[Zakiel Windlow]

Thank you very much for the reply Astrid!

Yap, you said it: it's is a good puzzle :matte-motes-confused: but I don't want to give up, yet.
I'm going to try your suggestion. Dunno, maybe it works. At this point I don't know what to do, so every suggestion is welcomed.

And as far I know, it is just an x-mirror problem, because the topology of the models seems right.

Dunno, maybe has something to do with the gizmos/axis and rotation of the model before exporting?
Thought was that when I found this post:
http://blenderartists.org/forum/showthread.php?179518-Rigging-in-x-axis-(Blender-2-5)

Now, if you compare the local axis of the first 2 meshes with the axis of the test box, you can see that:
- The first 2 meshes use the -X/X axis for forward and -Z/Z axis for up.
- But the "test box" uses -Y axis for forward.

Thought this could be the cause, but while I was writing this, I've rotated the local axis of the test box (to X forward, Z up) in 3DS Max, exported, imported, applied weights and nope, X-Mirror won't work.

About the workflow of the first 2 meshes:
1) 3DS Max: Basic/box/low poly modelling  >> 2) ZBrush: Subdivide and add details/texture >> 3) 3DS Max: Baking >> 4) Blender: Rigging/Skinning

But, in the case of the test box, I've just created it in 3DS Max and exported as .OBJ to Blender. This would be the first step in my workflow. Maybe something changes during every step? Dunno, I'm just throwing stupid ideas in here :matte-motes-sour:

[Zakiel Windlow]

UPDATE:
Well, now I'm feeling the lack of theory that would let me understand what is happening.

I've did some more testings with the "Test Box" and here are the results:
1) In 3DS Max I deleted half of the model, applied a mirror modifier and exported as .OBJ
2) In Blender: X-Mirror is working!! But ONLY with Topology Mirror deactivated.

Tested the same with a symmetry modifier and works in the same way.

Why did I do this test?
Because, in the case of the first two models, in the first step of my workflow. I modeled only one half in 3DS Max, then applied a Mirror/Symmetry modifier and jumped to ZBrush for the details.

Now, this is when I feel the lack of theory:
Why?? Why does it work with a mirror modifier applied before the export?
Because, if you look at the model, it's the same (its topology) with or without the mirror modifier!

Somebody can explain me this? Or link me some stuff to read abut, because in almost 4 years this is the 1st time I'm facing this problem u.u. I just wanna learn and understand what is happening "in the background".
Thanks again in advance.

 

[Gaia Clary]

i fear the problem is that the x-mirror weight paint implementation is not very good. It realy works only when you have a perfect symmetry that was "constructed" by blender itslef (by using the mirror-modifier for example). the problem is probably the order in which the vertices are stored.

Actually the weight paint tools are very likely to get an overhaul soon. To make them behave more expected and less picky. But no promise :matte-motes-whistle:

[Zakiel Windlow]

OMG Gaia!!
I really was expecting your answer, because all of these was driving me crazy!

Didn't know if it was my mesh, Blender, Avastar, the .OBJ exporter, .OBJ importer... Bleh

Hopefully I will find some workaround, like working on a real symmetrical mesh and then transferring the weights to the "non symmetrical" (it is but for Blender is not )...

Thanks again for your reply.
Now I can relax a bit and think in the solutions and steps to change in my workflow.