I finished meshing some glasses on Blender and I wanted to texture/colour them on Photoshop, so I unwrapped the lens and the frame (they are separate objects) into UV maps. The lens' UV map looks normal and bakes fine so I can texture them later on, but the frame is the total opposite.
As you can see, the actual UV Map of the frame is inside a white box which doesn't happen to the lens:
I've tried several settings when trying to bake the frame's UV map but when I click bake, it doesn't work. I've sat for 30 minutes waiting but the progress bar stays at the same place at the beginning.
I'm unsure on what to do so any help will be appreciated, and I can provide more information or upload the blend file if needed.
Imagine a real life globe. To glue the world's map on a sphere without paper folds at the top or the bottom one has to cut it like this
UV mapping works on the same principle. We unwrap a 3d model, as in we create a 2d representation of it, use the result to create a texture and then apply said texture to the model.
You CAN unwrap the mesh in many ways, but you SHOULD do it in a way that results in the least amount of stretching and the biggest uv islands ( bigger uv islands = better texture quality ). Keep in mind that in The Sims 4 all CAS items share the same UV space, so you should put your UVs only in the designated area for glasses
Clone any glasses, export the blend file, open it, select the frame, choose its uv_0 map, select everything with A, and look how it is unwrapped in UV editor. It may look like there is only one half of the mesh. The glasses are symmetrical, so both halves can use the same texture, thus one half's uv islands can overlap with the second half's. However, when you bake something with overlapping uvs, you get black spots. So if you plan on baking textures, you should move one half's uv islands to the side ( G X -80 ), bake the textures, move them back ( G X 80 ), edit the resulting texture by removing that unnecessary part.
Anyway, back to the reference you cloned and exported, select everything with A, Tools - Remove doubles with Merge distance set to 0,0001. Then in UV editor go to UVs - Seams from islands. This way you will get a better idea where exactly the seams are and how you should unwrap your mesh. Go back to your mesh, delete one half of it, select everything with A, set that template I gave you as the background image, select edge loops by Shift-Alt-RMB-clicking on them, mark them as seams ( Shading/UVs - Mark Seam ), unwrap ( Shading/UVs - Unwrap - Unwrap ).
Last Edit: Mar 21, 2020 14:34:39 GMT -5 by mauvemorn
I have come across another issue regarding the glasses in-game, they appear glitched when in both Blender and Sims 4 Studio, they look fine. Would I start a new thread on this or would it be fine to ask here?
Post by StellarElite on Mar 28, 2020 11:53:39 GMT -5
I'm having similar issues as the OP so I hope it's ok that I post here I read the guidelines for posting and it seems ok but let me know.
Quick back story lol. Basically I'm also creating glasses and having a really really hard time figuring out how to map it so I can easily bake it and colour the highlight/shadow on it in photoshop. Glasses don't come with normal/bump maps and I tried to add one but that went nowhere fast. Baking rarely works for me no matter how perfect I mesh (my current mesh is perfectly topologized, no inside faces etc) it's always a mess so I need to go into photoshop and fix weird black pixels all over the place etc.
After studying EA's and another creator's glasses uv map I'm not sure how they mapped it to make it so simple and rectangular. No matter which UV unwrap option I choose I get some variation of that really detailed literal interpretation of my mesh. Here's an example:
EA UVMAP: CC UVMAP: MY UVMAP:
I can tell they're cut in half so that's good to know how thanks for that!But I'd really like to be able to get that rectangle type shape so I can paint in highlights/shadows easily. I have a feeling it may have to do with the way I've marked seams so I'm going to play with that while I wait lol. If anyone has any insight I'd be forever grateful thanks!
When the mesh is unwrapped automatically, (taken the seams are in the right places, as in the uv islands do not "curl" onto themselves), the distance between uv vertices corresponds to that of a 3d model. When you move them further apart from each other, the distance increases. The textures, once applied, will be stretched. If you move them closer, the textures will shrink. This is what will happen when you try to change your uvs from accurate to straight. You will paint a straight line (highlight) in photoshop, but it may become wider in one place and thinner in another once you import this texture. What you should do instead is add more seams like this, join the frame with the glass, unwrap
Then select only the left half of the glasses' uvs, flip them ( UVs - Mirror - X axis ) and place them on top of the right half's uvs. Then scale them UNIFORMLY to take up all the space meant for glasses, bigger uv islands = better texture quality. With sync enabled you select one half of the mesh, click Ctrl L, in UV editor move this half away from the area meant for glasses by a specific number ( G X 100 for example). Then bake the texture Then move the uvs back ( G X -100)
Then edit the texture by removing the unnecessary
And don't forget to separate the glass and change the cut number
The reason you get black artefacts is because either the mesh clips into another or the uvs overlap with each other. For example, if you have a reference mesh in the scene, it probably overlaps with yours. You have to disable rendering for it by clicking on the camera icon next to its name in the outliner (where eye and cursor icons are) If your glasses clip into head in the ear area, disable rendering for the head.
And, once again, make sure uv islands do not overlap with each other or themselves.
Last Edit: Mar 28, 2020 14:58:00 GMT -5 by mauvemorn
Post by StellarElite on Mar 29, 2020 8:09:11 GMT -5
After I posted I realized that I missed that part where you use make seams from islands. Just selecting the mesh and looking at the uvmap doesn't tell you much but this is gold!! Thank you!
This is all amazing information thank you I will give all this a try. I didn't think about reference meshes either this is also the missing link that nobody says when you search crappy artifacts when baking. All the threads I waded through and not one mentioned this lol. I spend a lot of time making maps immaculate and so was banging my head against the wall on this one. Where's the overlap??? lol Thank you again!
After my last post I actually tried to go ahead with half the mesh. I cut it in half and then started marking seams. From what you've just posted it looks like I should mirror and join everything back and then just select half so I will go that route and see how it goes. Thank you very much for your help! 8-)
Yeah, making meshes symmetrical will save you a lot of time. You can add mirror modifier from the very beginning without applying it, by the way, whatever you do on one side will be automatically duplicated and mirrored to another
Last Edit: Mar 29, 2020 8:55:44 GMT -5 by mauvemorn
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