First post here so apologies if this was already discussed.
I am trying to create a basic shader for a horse I made using anisotropic but I can’t seem to get rid of the UV seams.
The model is using 3 UDIMs.
I painted the flow map(tangent or directional normal whatever you want to call it) in Mari. I painted in Z up using a Z-up version of the model and then turned it into Y-up before exporting.
I tried both Y-up and Z-up World space normal versions in Unreal but no luck.
I should also clarify that I am very new to Unreal in general so maybe I’m setting the aniso wrong somehow?
How do I get rid of the seams? Appreciate some help.
Honestly I don’t have any real experience with UDIMs or anisotropy, so this is my wildly ignorant guess but Unreals tangent space is based on UV channel 0. So my hunch would be that it could impact how anisotropy/UDIMs behave.
First, make sure that your UV seams are not visible in your 3D modeling software. If they are visible, you may need to adjust your UV mapping to create a more seamless texture wrap. It’s also important to ensure that your UV islands are not overlapping or stretching.
Another thing would be to check the smoothing (groups and splits) on your model. Often times people put them on models to improve the quality of the normal map bake but the in-engine model should have no splits or hard-edges. One way to check is to re-import your model with only 1 smoothing group applied.
If the problem still persists than it is most likely a mismatch between the tangent spaces of the UDIM slots. I am unfamiliar with how UDIM’s inside Unreal but I would recommend watching some tutorials and ask ChatGPT if you are stuck.
Next, you should check the settings of your anisotropic shader. Make sure that you have set the correct axis for your flow map, as this can affect how the anisotropic highlights are applied to your model. You may need to experiment with different settings to find the right combination for your specific model.
Another thought: I would recommend looking into using Substance Painter to paint your flowmaps.
