Looks like you are correct. I don't know what I saw earlier...Importing a 2048 x 2048 texture and the exporting the texture does retain its size.

"We often compare ourselves to the U.S. and often they come out the best, but they only have the right to bear arms while we have the right to bare breasts"
Bowser and Blue, Busting The Breast

I can suggest one more thing.
Sometimes RL apps do not properly identify normal/bump maps when importing.
You have to reload them manually and make a proper selection (normal or bump).

Do the following:
Right mouse click on bump map, then select Copy.
Right mouse click again and select Paste.
At the prompt do a proper selection (Bump in you case) and see if that made a difference.

The resolution of the maps should not change unless Max Texture Size is set to a lower resolution in 3DXchange during export.

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76% of original size (was 661x19) - Click to enlarge

The grill is purely bump map and the bump map has very distinct/sharp color changes.

I have to double check my theory but I think I noticed that iClone seems to be using lower resolution version of  my texture maps. This would explain why the text is more blurry and why the bump map details are not sharp.

If I am not mistaken, the texture maps that I imported were 2048 x 2048 in resolution. However, when I ask iClone to edit the texture map, provides a 1024 x 1024 resolution file.

"We often compare ourselves to the U.S. and often they come out the best, but they only have the right to bear arms while we have the right to bare breasts"
Bowser and Blue, Busting The Breast

The grill is purely bump map and the bump map has very distinct/sharp color changes.

I have to double check my theory but I think I noticed that iClone seems to be using lower resolution version of  my texture maps. This would explain why the text is more blurry and why the bump map details are not sharp.

If I am not mistaken, the texture maps that I imported were 2048 x 2048 in resolution. However, when I ask iClone to edit the texture map, provides a 1024 x 1024 resolution file.

"We often compare ourselves to the U.S. and often they come out the best, but they only have the right to bear arms while we have the right to bare breasts"
Bowser and Blue, Busting The Breast

Hard to suggest without having the model and texture maps.  But I never had any problems with bump/normal maps in iClone (I mostly make normal maps though).
Although what I see in a grill, is that mesh is smoothed. You need sharp edges. Bump map is not going to do anything there.
Either try to use auto-smooth in 3DExchange, or mark grill edges sharp in Blender and apply Edge Split modifier.

So it turns out that part of the problem was Strength setting. I triangulated the mesh and then raised the Strength to 100%.
This kicked in the bump but rather poorly compared to what I see in Blender.
Looking at the comparison in the screen shots below, you can see that the Blender version had a grill that was uniform on both sides, the lettering on it was clear, the signal lights had a vertical lined texture, and the door line and handle were present. Looking at the iClone version, the grill seems to be divided into two parts (as if the normals were facing the wrong way for half the grill...which they were not), the lettering on the grill is blurry, the detailing on the signal lights is gone. Only the door outline and handle seem to be fairly well reproduced.

76% of original size (was 661x19) - Click to enlarge    
I have tried playing with the strength but the signal lights details never appear. I have also tried using the displacement with automatic bump setting but that also does not work.

As can be seen, the Delorean is one mesh with a single material so it is not possible for the bump map to be applied to part of the mesh but not other parts.

76% of original size (was 661x19) - Click to enlarge

It looks to me like the sensitivity of the RL bump map implementation is unable to pickup the subtle height differences in the bump map that Blender is able to pick up.

Any other suggestions?


"We often compare ourselves to the U.S. and often they come out the best, but they only have the right to bear arms while we have the right to bare breasts"
Bowser and Blue, Busting The Breast

I will give that a try. That could also be the problem with the tire geometry not loading correctly.



"We often compare ourselves to the U.S. and often they come out the best, but they only have the right to bear arms while we have the right to bare breasts"
Bowser and Blue, Busting The Breast

The original model (in Blender) uses Bump maps not normals, so that should be correct.
The model is made up of one body mesh which includes everything except for the tires. The tires are their own meshes. 

ampertox (9/13/2021)

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You could try to experiment putting the bump into the displacement with auto-assign to bump, then try to adjust roughly displacement to see if there's any changes.

Thanks. I will try that.



"We often compare ourselves to the U.S. and often they come out the best, but they only have the right to bear arms while we have the right to bare breasts"
Bowser and Blue, Busting The Breast

Looks like you have ngons issue here. Mesh with ngons imported as OBJ does not look good in any app: https://forum.reallusion.com/FindPost439816.aspx
Might happen after using Limited Dissolve.
Try to triangulate faces before exporting from Blender and see if that makes difference
(Blender being a modeling app does better job triangulating with beautify option, than 3DX).