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unstable
11-29-2015, 08:06 AM
Just wondered if this was possible. Here is what I've done. I created two models, call them sphere 1 and sphere 2. Sphere 2 is a copy of sphere 1. I create a UV map for sphere 2 and then froze the object so I could import it into another software package to paint. Once I got the UV painted, I wanted to apply it to sphere 1, but realized I failed to make a UV for sphere 1. Can I somehow make a copy of sphere 2's UV and add it to sphere 1? I tried exporting sphere 2's UV as an EPS and importing the EPS into sphere 1's model but it didn't appear as a UV map like I thought it would. Thanks

Markc
11-29-2015, 08:44 AM
You didn't use 3D Coat to paint did you?
If so you can export the UV'd object with textures.

unstable
11-29-2015, 09:16 AM
You didn't use 3D Coat to paint did you?
No, I didn't.

JoePoe
11-29-2015, 09:23 AM
Not really an answer on transferring the UV but....

1: did you save a version of sphere 2 after the UV was made but before you froze it? If sphere 2 was a copy of sphere 1 then just use that.
2: You're calling the objects spheres.... are they simple objects? Is the UV a simple automated unwrap or a fairly simple one click ABF? IOW....Did you push points around after the initial unwrap? If not, Just create it again on sphere 1 and apply your painted image.

unstable
11-29-2015, 09:50 AM
1: did you save a version of sphere 2 after the UV was made but before you froze it? If sphere 2 was a copy of sphere 1 then just use that.
2: Your calling the objects spheres.... are they simple objects? Is the UV a simple automated unwrap or a fairly simple one click ABF? IOW....Did you push points around after the initial unwrap? If not, Just create it again on sphere 1 and apply your painted image.

1. Actually, I do have a copy of it before freezing. But I wasn't aware that if I resize an item and move it and rotate it on the map after freezing it, it pretty much voids the one I did prior to freezing. I know that now though. :D And it makes perfect sense as to why the texturing would be all mis-mapped. It sounds like I have to start from scratch again. I've only spent 2-3 days trying to create a UV map I can use all the way through. By the time I get one that works, I just hope I remember the correct steps and not some of the bad ones. Hehe.

Skonk
11-29-2015, 09:51 AM
You can use the surface baking camera in layout to bake the texture of one object into the UV's of another. Even if the UV's are very different between the 2 objects.

bazsa73
11-29-2015, 10:12 AM
You can use the surface baking camera in layout to bake the texture of one object into the UV's of another. Even if the UV's are very different between the 2 objects.

That never came to my mind! I always learn new things on these forums. Thanks.

unstable
11-29-2015, 10:17 AM
You can use the surface baking camera in layout to bake the texture of one object into the UV's of another. Even if the UV's are very different between the 2 objects.

Do you happen to have a link to a good tutorial for this or some other reference? I'm having trouble wrapping my head around this. Do send both objects to layout to bake one object's texture to other's UV?

Skonk
11-29-2015, 11:14 AM
The only time I've done it myself was to bake normals from a high res mesh onto the UV's of a low res mesh; and the normals were just generated using a surface node on the high res mesh so should work the same for any surface.

https://www.youtube.com/watch?v=DWBCfoc8u1I

This is what I watched to learn how to bake the normals.

The gist of it is that you have both models loaded and in the same place in the scene (so they overlap); you tell one of them to be hidden from rays/camera while you bake the other model.

It goes over it in the first part of the video anyway.

jeric_synergy
11-29-2015, 02:07 PM
You can use the surface baking camera in layout to bake the texture of one object into the UV's of another. Even if the UV's are very different between the 2 objects.
!!!??? How does that work??

Skonk
11-29-2015, 03:37 PM
Load the 2 objects in to layout and have them both set to the same position.

Set the scenes light to 0% brightness and ambient to 100%

Select surface baking camera and select the mesh and uv of the object you want to bake into (usually the low polygon model).

Set the "offset from surface" property of the surface baking camera to a value large enough to hit any raised up details of the higher res mesh (e.g. 100mm).

Select the object you are baking into (low res) and hit P for properties, goto the Render tab and tick unseen by rays AND unseen by camera.

Then hit F9.

You may need to tweak settings depending on your objects but what should happen is that the surface baking camera which is assigned to the untextured model (and baking into the UV map that I assume you created on the untextured model) bakes but since the object it's self is not seen by rays or the camera, it's own surface doesn't get rendered.

Instead, due to the offset, it will pickup the surface of the textured object and render that into the UV's of the untextured object.

This can also be used with a node that renders normals onto the surface, to bake a normal map from a high res model onto the UV's of a low res model; as showed in that youtube video I linked.

Skonk
11-29-2015, 03:58 PM
I've attached a series of screenshots showing the settings for a very simple pair of objects. As long as the textured object is reasonably close in shape to the untextured one, it should work (you need to set the baking camera's offset accordingly of course).

In this case; the textured object is just mapped using Cubic projection and doesn't have it's own UV's; but it really doesn't matter how it's textured. It's the second (lower poly in this case) untextured mesh that has the UV's and it's this mesh that's selected in the surface baking camera.

I've used with along with the DPKit NormalCast node to create normal maps from higher details models (for use in Unity); but that's what the YouTube link above is explaining (thanks to Petter Sundnes).

Hope this helps.

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Surrealist.
11-30-2015, 01:59 AM
Surface baking is an option. A fair one. And always good to know.

It is far more elegant solution to simply transfer UV maps from one object to another. Especially if you are dealing with more than one map (bump spec etc). Hopefully this will come to LW soon. You can copy and paste UVs from one object to another in Modeler but results seem flaky if the objects have a different resolution.

There are other apps that can do this. If you have Maya or XSI, you can transfer UVs.

If you want to save time on this project, I am happy to do the UV transfer for you using one of these apps if you don't have them. Free of charge of course.

While I hate to offer the "better to do it in another app" solution, this is one of those things that LW just does not do, that I am aware of. Unless there is a plugin. But it is a vital thing to have and be able to do. So it is hard to live with the workarounds - in my opinion. :)

unstable
11-30-2015, 06:43 AM
You can copy and paste UVs from one object to another in Modeler but results seem flaky if the objects have a different resolution.

I did copy the map from the second object, but that changes the poly count as well because the second object had been frozen. Unless I'm doing it wrong. Maybe that is what you meant by different resolution.

Surrealist.
11-30-2015, 08:07 AM
Well it should not change the poly count but what I got was unpredictable results due to a miss match of polycount. Using copy and paste from the UV Map menu.

Blender has the same issue. But it works correctly in Maya or XSI.

The offer stands and you are good to go. :)