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I'm using Cycles Node to create materials in Blender. Material has four image textures connected to a Principled BSDF. Base-color, Metallic, Roughness, Normal(through a Normal Map node).

Everything is fine in Blender. Then I export it to FBX, setting Path Mode to Copy and Embedding Textures using the small button to the right.

Everything is fine up until this point. I have my FBX file, then I import said FBX and that's when the problem starts.

It imports correctly, with Textures connecting to BSDF as they should be. But all their Color Space settings were set to sRGB(which was to be Non-Color) and the Normal Map node's value(which was 1) becomes 0.14.

Why does this change in settings occur? I know that material exporting doesn't work splendidly from environment to environment, but is this normal? Or Am I doing something wrong?

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  • $\begingroup$ I think the color space being switched to sRGB is because the FBX format doesn't allow to specify which color space should be used and sRGB is just the default that gets assigned when Blender imports the file. The deviation in the normal map strength sounds strange though. Can you share your .blend file (with packed textures)? blend-exchange.giantcowfilms.com $\endgroup$ – Robert Gützkow♦ Oct 16 '19 at 13:45
  • $\begingroup$ The normal map strength seems to be caused by the conversion in line 1429 import_fbx.py. Since your strength of 1.0 / 7.142 = 0.14 it apparently stores the correct value in the fbx, but this "guess work" conversion returns a different value. I'm not sure when this conversion would be useful. Might be worth discussing on devtalk. Your project file isn't needed though. $\endgroup$ – Robert Gützkow♦ Oct 16 '19 at 14:00
  • $\begingroup$ Thanks, I think the receiving end of the FBX has to set up the material themselves, I just downloaded a free model with similar setup and it just has textures as files, setup not included. I was guessing that the customer would expect to see a complete result Voila! when they open an FBX, but that's not the case I think. I would be happy if you can confirm on this too since I'm just guessing at this point. Does the receiving person expect FBX to work without making any adjustments to it? $\endgroup$ – IndividualGames Oct 16 '19 at 14:24
  • $\begingroup$ The answer is: It depends. FBX allows to define material properties, but both the software writing the file and the one reading it, need to put the information to good use. If the software writing the file doesn't add the information, there is no chance to import it like the original model. Likewise if the software importing the model doesn't support the whole FBX specification, then it will not be able to display it exactly the same way. FBX format is quite notorious, see: code.blender.org/2013/08/fbx-binary-file-format-specification $\endgroup$ – Robert Gützkow♦ Oct 16 '19 at 14:48
  • $\begingroup$ That being said, there is no clear answer as to what the user expects when receiving an .fbx file. I'd assume that most people would think it should work out of the box. $\endgroup$ – Robert Gützkow♦ Oct 16 '19 at 14:57

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