Combining multiple UV maps and textures

[bdubyah]

I purchased a model from sketchfab to use in a game, but the model is in multiple pieces with each having a UV map and it using 4 different textures overall.

What would be the best way to clean it up? I was thinking if I could just get the 4 main UV maps combined into one, kind of in a 2x2 arrangement, I could just use GIMP and combine the 4 textures in the same layout. But I'm not sure how to accomplish that or if there is a better way.

[The Renderer]

The simplest way (unless there's an add-on I don't know about) would be to do the following:

1) Create a new big texture by combining the 4 you have into a 2x2 grid using e.g. Gimp.
2) Load that big texture as texture for all 4 objects, then scale and move the UVs so they fit the new location of their old texture on the new big texture (i.e. the UVs then each occupy only a quarter of the new texture). If the textures are all the same size you should be able to scale the UVs by 0.5 and move them by a quarter of the pixel number of the new big texture in each direction to align the UVs perfectly to their old texture.

Example: Your textures are all 1024x1024. You combine them into a big 2048x2048. The first object's old texture is located on the bottom left of that big texture. Scale the UVs of this object by 0.5 and move them 512 to the left and 512 to the bottom. Second object's texture is to the top right, so scale its UV by 0.5 and move it 512 to the right and 512 to the top.

3) Make sure the UV maps all have the same name
4) Select all 4 objects and hit Ctrl-J to join them (and their UVs) together.

You can also do step 2) after step 4). Will give you the same result, it's just less neat to work with since they will all overlap at that point.

[bdubyah]

Awesome! I think my brain was fried at that point last night. I never thought about scaling and moving them before joining them.

Thanks!

[Pte Jack]

https://www.youtube.com/watch?v=pa8ubV8YVqg

Is the way I do it

[The Renderer]

Originally posted by bdubyah:

Awesome! I think my brain was fried at that point last night. I never thought about scaling and moving them before joining them.

Thanks!

No problem!

Originally posted by Pte Jack:

https://www.youtube.com/watch?v=pa8ubV8YVqg

Is the way I do it

That's for combining multiple UVs of one object. OP was asking about combining several objects with different UVs and textures. Very different thing.

[Pte Jack]

Sorry, my bad... Thanks for pointing that out Render but I have something on that as well This is combining multiple textures into one sheet for Valve Power of 2 type textures using GIMP...

https://www.youtube.com/watch?v=1itUAKyfMVM

[bdubyah]

I had read through that last night. Was my reference for combining the textures. Just had to figure out the UV side. Thank you though!

Think I just needed to sleep on it. Lol.

[Pte Jack]

This is the long winded guide for that video.

https://steamcommunity.com/sharedfiles/filedetails/?id=821774883

Also, there is a Blender tool out there that uses another plug in to combine multiple textures into one sheet. The plug in is CATs Blender Tools by MichealDegroot (available here https://github.com/michaeldegroot/cats-blender-plugin ) and the the other plug in he calls from Optimization panel is a plug in called an Atlas Generator by Shotaryia.

The atlas actually combines all the textures used in a model to one sheet, arranges all UVMaps to use the new texture, reassigns the materials and textures to point to the new texture AND cleans the old materials no longer used from the project.

https://i.imgur.com/OiIKo05.png

This is the model using that one combined texture

https://steamcommunity.com/sharedfiles/filedetails/?id=1665139700