Genesis 3 to Blender via mcjTeleBlender3. How is UDIM working in Blender?

Bryson Jack

I feel like there is some strange magic going on. I exported/imported my Genesis 3 character to Blender via mcjTeleBlender3 and there is only 1 UV map with all the UV Tiles offset..obviously UDIM, but Blender doesn't support UDIM. How is this actually being done? Why is this actually working? I would love to know because I could use this on my own projects. I don't see any special scripts or UV offset values anywhere and I really don't believe that Blender is using the _1001, _1002, etc, in the file names.

 

Also, I couldn't find anyway to search the forums. Can anyone help me find the search feature? All I can find is Search Store.

 

Thanks to anyone who can demistify these things for me.

Cris Palomino

Many programs have begun to support UDIM.  All G3 models are set up this way.  In the past, there were times you needed UDIM.  The method I explain further down to manually collapse maps can be used in reverse, on like G2 figures, to separate the maps as in G3.

You can do one of two things.  You can collapse the UVs.  It's an option for obj export in Daz Studio.

The other way is to select all the parts of a map.  Torso is only the torso, so you select it through materials and it should light it up in the uvs.  Check for the size of the texture as that will determine how much to move.  Torso is one tile over, my texture size is 4096 pixels square, so I use G followed by X and - (minus) 4096 and it moves it into the first tile space.  For the other maps, rather than do math, just move over by 4096 till you reach the first tile.  

With the uvs stacked over each other, you just access them by selecting the materials in the materials panel.  Save textures by having only the parts of the map, you want to create, selected.

Bryson Jack

Cris,

Thanks for your reply. You actually answered a question of mine that I hadn't even asked yet, which is how to collapse multi-tile UVs if I so desired it.

I actually tried to follow the steps that you provided and got hung up an a point. The arms for instance are on tile 4 and it is a 4k texture. Tile 4 minus the first tile, would dictate that I move the UV tile either 3 spaces to the left OR minus 12,288 in the X axis as I understand your instructions. The values, as you can see in the image, are neither of those numbers, however the highlighted area does reflect the value that I would like to move the UVs, but I just don't know how to move according to the highlighted values show in the parenthesis.

 

In addition to figuring out how to do what you were describing, what I would really like to know is how Blender is actually using the mutli-tile UVs properly. Each texture map should be operating in the 0-1 UV space, but the UVs are offset so I don't understand how the UVs that are offset outside the 0-1 space are displaying their textures properly in the 0-1 UV space. There are Mapping nodes wired to the UV texture coordinates and they are set to Point, but every single tile outside of the 0-1 UV space that is functioning properly share the same setup AND VALUES....so that is what I don't understand. What is telling blender that the UVs are offset and how to display them properly with the material/texture images?

Bryson Jack

Actually, it just occurred to me that the texture in the 0-1 space is tiling or repeating over and over so that is probably why it just works. I could nuke my question, but assuming that I did answer my own question, I will leave the "dumb question" posted in case it helps anyone else out, even if it is embarassing :)

 

I am still interested in figuring out how to move UV tiles.