Hi! blender beginner here. Struggling with bump maps. Made a bump map with gimp. Pyramid ramp (center black, corners white). I am seeing stripe artifacts once applied as bump map to a plane. No difference between eevee or cycles. What am I doing wrong?
Try change color space to ânon colorâ.
But this could just be a moire effect between texture and resolution. You could try make a stepping gradient texture.
Thanks for the reply. In blender 3.0.1 I donât have the option to chose ânon colorâ. I donât think itâs a MoirĂ© pattern here that Iâm seeing, but a problem with the way I create the bump map in gimp using the gradient tool.
Only Linear and sRGB ??? Works for meâŠ
Youâre getting stepping because the .png has 8bit color values. So it only has 256 different height values. Try authoring the image in GIMP with 16bit per channel.
Thatâs strange. Only if I use 3.1.2 I get the same options as you do.
Good call. I used the default âautomatic pixel formatâ which resulted in 8-bit grayscale. Now Iâm enforcing 16 bit grayscale.
hd_frame_bump_2.png: PNG image data, 1024 x 1024, 16-bit grayscale, non-interlaced
Well, thatâs an improvement, but doesnât solve it for good. The stepping is now just âfiner grainedâ so to speak. I just have the impression, that my bump map screws with some sort of interpolation blender is applying here.
Hi @e11bits,
The banding is a limitation of bump maps in general. As they are gray scale images they can only represent a single offset direction, they cannot represent angular information, like the slope of a pyramid side, so it appears stepped. A higher resolution will not mitigate this. However, using even a really low normal map ( this is 256x256) will give better results:
be sure to set the image type to Non-Color:
Cheers,
Dj.
ps . Normal map node should be set to Tangent space - Not Object space - I forgot to change it back.
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You want this completly without stepping? I guessed you want stepping but with an even pattern.
This is not possible without steps if the detail gets zoomed in.
You could use a gradient texture cause it has an infinite resolution.
gradient_pyramid.blend (105.2 KB)
Hi all! Thanks for all the valuable advice.
I now did get the result that I wanted after I found my mistake in creating the bump map. I initially was using 8-bits, as @kryp pointed out (also by NiCapp on blender.chat). But just saving it with 16-bits did not change the image itself. Only the file format the image got saved was changed. After creating an image explicitly with 32-bits (or 32-fp) and saving it with 16-bits format, I got the expected result. No steps (or other artifacts).
These are the settings I used in gimp:
(if 32-bit floating-point or integer did not seem to make a difference)
I guess I should create a gimp image creation template to not forget about those settings! 
Thanks again all for taking the time to look into this and give me your feedback.
PS: Yes, I know about normal maps, but I wanted to see what I was doing wrong here
PPS: @DamianJ What tool did you use to create that normal map?
PPPS: Iâm sure procedural textures are the way to go, but right now I donât feel comfortable enough to just be using them without knowing whatâs going on
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Hi,
I did it in Blender - itâs sometimes quicker to model and bake a texture so I made a simple pyramid ( plane â edit mode â selecte opposite vertices â press âjâ â select other corners and new middle vertex â press âjâ â select middle vertex only â move up â done ) and baked itâs normals onto a plane above it - effectively I was doing a Hi-res to Lo-res bake.
Dj.
Ah cool! Have to try this one day!