Large
unicornsammich1

complex UV maps?

Hi everyone! I am running into a small issue that I can't seem to find a way to kind of optimize my UV map. I attached a copy of the way my model is unwrapping. I know that I should adjust the sizes of the islands but how do I get the object that are exactly the same to not repeat on the UV map and the mirrored things not to repeat. I'm new to this process so any advice would help. 

this is the model I'm unwrapping. 

This is the way the UV default unwraps. I know the larger items need to be resized and the overall sizes of the islands need to be more regular across the board.

Thanks for any and all advice!

  • Largecrew

    Hi unicornsammich1 - The auto UV layout operation is good for quick and dirty layouts but not so much for legit character models. I recommend checking out the 2nd chapter of the "Building Modular Game Assets" course. I go over the process of organized UV layout including duplicate pieces for maximized texel density.

  • The way I did it with these two characters here:- https://www.cgcookie.com/t/557-game-res-poly-chetan
    was to use mirror modifier. I applied the modifier after unwrapping the model.

    Your model is symmetrical so you can delete half of the mesh, then unwrap it. That way mirrored parts will overlapp each other giving you a lot of space to have better texel density. Also, If this is for games, I think it is better to have less seams because it will take less calculation(correct me If I am wrong, please, I am also learning.) and give more performance, so try to merge the seams where ever you can.

    Also, that is a great model.

  • Large

    Really Nice model well done. 

  • Large

    Thank you so much!

  • Large

    thank you so much!  And it is for a game! I think I may have added too many seams. I suppose its not so important to not have any stretching at all since the character won't be viewed super close. I appreciate your feedback! I will definitely give this a try.

  • Large

    Thank you so much. I am ganna go and take a look at that now. I really appreciate the help!

  • Large

    Yes, you have far to many seams. Here's the file.

  • unicornsammich1  Ok, a couple of rules that you might want to apply to it and you should be good to go. (Lovely mesh by the way). 

    1. Whenever you unwrap stuff that is not organic and will not deform you want to cut your seems at a 90 deg. angle, since the normal, soft and round detail from the high poly will be baked on the sharp edges from the low poly. 

    2. UV editing is an art of it's own, which means that it has to be clear and easy for the texture artist who, for instance, does only photoshop and wants to add some cool stuff to your textures, or texture the whole thing altogether. And again, the easiest way to do that (and the only way that reduces pixelation after the bake to nothing) is to keep the unwrapped shapes in the UV image at 90 deg angles. 

    3. Use up as much texture space as possible without too much discrepancy in the texel size.

    dolores74 The image above unfortunately isn't the best way to do that since as you can see it's just a single cut along the side of a cylinder which causes undesirable deformation in the UV image editor (since it's not a plain cylinder, but a cylinder that has faces extruded in a perpendicular fashion) and it would be very difficult for a texture artist to work with. So I agree with you that she does have too many cuts, but what I don't agree with is that the solution is to take it down to one single cut - the bake would be bad. What you want to do is do a planar / normal layout for the front of the cylinder and then a cylindrical seam for the soft, rounded side in the least visible place that you then get rid of nicely by using the passthrough layer in Substance Painter 2 which basically allows you to get rid of seams. 

    So the choices that I'm left with with more rounded shapes like the handle below are either to cut it in undesirable places and then mask the seams OR accept the fact that there will be some minimal stretching here and there (which is what I went for in this case).

    Please take a look at the image below, my latest project ilustrates this point - if it doesn't make sense please ask. If any of the terms I used in the explanation don't make sense - ask. My UV layouts were so bad last month that I got really angry, spent the last 100+ hours learning about it and I will be happy to save you this horror. 


  • Large

    Thank you so much! This actually helped me visualize it much better. I am going back and redoing quite a few of the seams I previously had. I think I was way too focused on making something that had absolutely NO stretching. But that isn't necessary or realistic with my model. Thank you so much for the advice. 

  • Large

    The main reason this wouldn't work for me is because that middle cylinder is actually a very different texture. I added a seam on each side to make some ease to adding the textures but I did indeed have FAR too many seams. Thank you so much for your advice. 

  • unicornsammich1 Happy to help Ma'am ;)