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View Full Version : replace low poly mesh in layer with high poly, but keep UV map?



3dWannabe
04-21-2011, 10:44 PM
I'm trying to replace a low poly mesh in a layer with a high poly mesh of the same object.

But, even if I copy the UV map, it disappears if I delete the mesh before copying the new mesh to that layer.

How can I accomplish this, or am I making a fundamental mistake, assuming that I can use a UV map and surface texture for low poly version of an object with a high poly version?

Thanks!

nickdigital
04-21-2011, 11:03 PM
You could try to do a poly-reduction operation on your hi-poly mesh. But you can't just copy the UV from your high-poly to your low-poly as the UV info is associated with the mesh.

3dWannabe
04-21-2011, 11:19 PM
You could try to do a poly-reduction operation on your hi-poly mesh. But you can't just copy the UV from your high-poly to your low-poly as the UV info is associated with the mesh.

Actually, I'm going in the other direction, trying to replace a low poly mesh with a high poly - which I hope to use in Fusion as an FBX mesh to get around Fusion's lack of sub-d for FBX meshes.

Are you saying I can't copy the UV from my low poly to my high poly as the UV map is mapped to certain points on the mesh?

Or is it mapped in a relative way, so that if they mesh had exactly the same shape, it would map ok, but there's some other problem with using the UV for one mesh with another mesh?

shrox
04-21-2011, 11:32 PM
...Are you saying I can't copy the UV from my low poly to my high poly as the UV map is mapped to certain points on the mesh?...

Essentially yes, move a point/vertex and you'll see the map distort.

stiff paper
04-22-2011, 06:45 AM
Will "mn_DrainBGVMap" help?

Mike Green hosts it on his plugins page:
http://www.mikegreen.name/

3dWannabe
04-22-2011, 09:44 PM
Will "mn_DrainBGVMap" help?

Mike Green hosts it on his plugins page:
http://www.mikegreen.name/

I've been playing around with this, and if I set it to single rather than multi, it gets everything but the outer and inner edges of the UV.

This shows the new UV highlighted over the existing UV.

So close!!! and yet ... so far.

Thanks!

stiff paper
04-23-2011, 05:07 AM
So close!!! and yet ... so far.
Now, I should say up-front that I've never actually needed to use DrainBGVMap, so all I can offer is what I consider to be sensible things to try...

But... looking at the image you've included...

Try unwelding all the points in the object you're transferring to, running DrainBGVMap and then merging points. I expect it'll cause some mess with points connecting in ways you don't want, but it might at least force it to include the polys at the edges.

Hmmm... I'm sure I've seen another way of doing this in the forums at some point, but I can't find it...

stiff paper
04-23-2011, 05:11 AM
And then there's this:
http://www.newtek.com/forums/showthread.php?t=40599
(...And I've never used this one either, so who knows whether it'll work? Edit: Ah... meshes have to be the same, so probably no good.)

In this thread, probiner offers up a solution (on page 2) that's a pain but he says definitely works (I knew I'd seen it somewhere):
http://www.newtek.com/forums/showthread.php?t=101476&highlight=mn_DrainBGVMap&page=2

3dWannabe
04-23-2011, 10:32 AM
thanks to all!

I finally used Lightwave's Maya 2011 "plug-in" of 'transfer attributes' to move the low poly UV to the high poly UV.

Works like a charm, the old texture with painting I created in 3D Coat maps 'spot on' to the high poly.

Interesting it takes so many pieces of software to make it all work.

I used Lightwave as a 'plugin' for 3D Coat to fix some ngon's from 3D Coat's retopology.

finaldetail
08-04-2011, 08:52 AM
hey 3D,

Is there any way you would be willing to upload a before and after or something like that? I have been playing around with some plugins and it seems like they are all saying they do the same thing (regarding UV) but I keep getting different results. I'd like to see what ended up satisfying your vision...

3dWannabe
08-04-2011, 09:22 AM
hey 3D,

Is there any way you would be willing to upload a before and after or something like that? I have been playing around with some plugins and it seems like they are all saying they do the same thing (regarding UV) but I keep getting different results. I'd like to see what ended up satisfying your vision...
Actually, I found that Mudbox will also do this, as well as the original program the model was created in, 3D-Coat.

When I sub-divided in Mudbox or 3d-Coat, there was a way to "sub-divide" the uv also, so the results were perfect (I forget what the exact steps was)

I believe it was slightly better than when I used Maya on a mesh that had already been sub-divided.

So, either Mudbox or 3d-Coat (3d-Coat has an educational version that could suck in your LW model, and then sub-divide it - think of it as just a plug-in for Lightwave).

I don't really have before/after, but the results were spot on.