Textures Stretch importing from Substance Painter to Maya

[Anonymous]

Hi everyone,

I'm really struggling to wrap my head around this. I've made a Tank Wheel in Maya as a low poly mesh, I unfolded and laid the UVs out properly. Then I imported my mesh into Substance Painter and painted it there and was happy with my work. There was NO STRETCHING inside of Substance Painter. However I noticed that on one specific UV shell once I added the textures into Maya using Arnold and a aiStandard, that there was really bad stretching. Now I checked the density of all my UV Shells and they are all the same so it doesn't make sense why there is stretching. Is it possible that its to do with going from low poly to a smoothed Preview? Or that I didnt lay out the UVs correctly? Please helpas I am very new to Texturing complex models. Bellow is some screenshots of what im dealing with.

Thanks in advance!

[damaggio]

Thanks for the images, that tells me that indeed your Uvs are not fully unwrapped in Maya in those poly faces and need to be retouched in Substance, Just find those faces and relax them  and repaint.

[Anonymous]

Thank you so much for the fast reply. Awesome! So Ill go back and edit my UVs in that particular shell! Im a little new to Texturing so im not to sure how to relax the UV Shell. Is it under the smooth tool? The problem only seems to occur when I go from low poly to smoothed preview as the UVs get stretched in the process. Im wondering if im better off texturing the object as a sub-D? only thing is my entire model is so heavily detailed that it causes my PC to lag once everything is smoothed.

[damaggio · Accepted solution]

No, the problem is occurring in the low poly model you can see in your image, it will also stretched in smooth , shown in your image.

You can relax the shells with the problem or you can select those faces and do a new automatic mapping and sew it back together.

The whole face of that wheel could be one UV shell and unwrapped, you wouldn't have any problems, then  separate shells for the holes inside the thickness of the wheel.

You should also avoid red shells .

The texturing is looking good, keep at it.

[damaggio]

Also I would have kept the bolts as separate models like in the real tank, models should have separate parts like a real tank has.,by doing so you added a lot of extra work and unnecessary topology.(Specially bolts and nuts).

You can combine stuff at the end, that's okay specially if they have the same shader.

[Anonymous]

Wow thank you so much for the in-depth response! Its super helpful and your absolutely right in hindsight I should have kept the bolts separate the tank model is huge and has such tiny details that are all apart of a larger topology and I know I have my work cut out for me now. Im really struggling with the texturing side of things as I thought it would be a breeze to do but the process of unwrapping the UVs properly is a lengthy process. And now with the stretched faces it really sucks to go back and alter the UVs. But ill do what you suggested and give it ago by relaxing the stretched faces and hopefully it will work! Thank you so much!

[damaggio]

This is what happens with red shells when you render, unless your engine supports inverted Uvs.

[damaggio]

This is what happens with red shells when you render, unless your engine supports inverted Uvs.

[damaggio]

Well that's good, it won't take too long and you'll do a better job the second round, good luck.

[Anonymous]

Thanks for letting me know about the red UVs Ill be sure to flip them to the correct side so that it doesn't give an incorrect texture like that. Sorry to bother you again but I'm having a similar issue again with another section of the tank. This time its stretching at the seam of where one shell meets another and I'm so confused on how to fix it. I tried to relax the section of UVs and it made it worse By going to the smooth tool and dragging the relax button it only distorted it further. Have you got any suggestions on how to fix this? I attached a picture bellow. (I'm still mapping out each UV with the cut and sew tool. I'm not sure why this is happening but its happening at the seam/edge of faces that stretch when I smooth preview. 

[damaggio]

sorry i can't tell from your screeshot, can u upload that piece of the tank instead?