Hi,

here is the thing - I don't understand normal maps. I know they are supposed to work like bump maps and add hight to a surface. But it seems they do more than that? The seem to change the way thje light is being cast over an object. And that changes with the value of the normal map... or is it menat to be at 1 all the time? Or is it not good to use them together with bump maps?

An example...

on this ball there is only the colour map and the normal map at a value of 1, 0.5 and 0.05 (from top to bottom). The lower the value, the smoother the light/shadow seems to be?

Also, the ball has a subdivisdion level o3. If I turn that of, this is what happens... (normal map at value 1 again)

Normal maps and bump maps serve the same purpose so use one or the other but not both at the same time. Also, Im guessing you are rendering in Cycles? Cycles converts bump maps into normal maps. Some have said there are problems with normal maps in Poser and I would tend to agree because I've had issues with them myself. IIRC you are supposed to set them at a strength of 1.0. This ALWAYS results in way too much bump in the texture. Also keep in mind if you are using PBSDF for your textures that it's roughness is modulated by the bump maps/normal maps. That means the bumpier the map, the rougher/less shiny your object will be.

W10, Ryzen 5 1600x, 16Gb,RTX2060Super+GTX980, PP11, 11.3.740

Oh, I'm sorry, that was physical surface node, I forgot to mention. I still don't really know how to set up cycles.

 I also had strange things with normal maps for skins... the skin seemed darker somehow.

Ok, but that means I would skip the normal map and use bump. At least I know how that works and I can finetune the outcome with it's value.

Varnayrah posted at 6:07 AM Sun, 10 November 2024 - #4491204

Oh, I'm sorry, that was physical surface node, I forgot to mention. I still don't really know how to set up cycles.

 I also had strange things with normal maps for skins... the skin seemed darker somehow.

Ok, but that means I would skip the normal map and use bump. At least I know how that works and I can finetune the outcome with it's value.

Yes, if there is too much bump coming from a normal map that will darken the texture. It might also happen with bump maps as well.

W10, Ryzen 5 1600x, 16Gb,RTX2060Super+GTX980, PP11, 11.3.740

I'm playing with bump maps in the Physical Surface node. There is definitely "clipping" going on with regard to bump maps. If your bump strength  is too much it will clip off the peaks like would happen when recording audio too loud into a digital recorder. You have to lower the amount to below a certain threshold before it stops clipping the bump map and darkening the texture.

W10, Ryzen 5 1600x, 16Gb,RTX2060Super+GTX980, PP11, 11.3.740

Normally I use Cycles for everything including skin. Here is a quick Physical Surface skin you might want to try. You might need to alter roughness and bump amounts. I also use a HSV node plugged in so I can control the skin color a bit.

W10, Ryzen 5 1600x, 16Gb,RTX2060Super+GTX980, PP11, 11.3.740

To clear up the darkness, in the bump map and/or normal map image set the gamma to 1.

Sunfire's Creations

ghostship2 posted at 8:27 PM Sat, 9 November 2024 - #4491196

Normal maps and bump maps serve the same purpose so use one or the other but not both at the same time. Also, Im guessing you are rendering in Cycles? Cycles converts bump maps into normal maps. Some have said there are problems with normal maps in Poser and I would tend to agree because I've had issues with them myself. IIRC you are supposed to set them at a strength of 1.0. This ALWAYS results in way too much bump in the texture. Also keep in mind if you are using PBSDF for your textures that it's roughness is modulated by the bump maps/normal maps. That means the bumpier the map, the rougher/less shiny your object will be.

I'm not an expert but let me take a stab at this.

I think you can reduce the strength by plugging your normal map into the cycles NormalMap node, that allows you to adjust the Strength. (If you're starting with a height map, and not a normal map, you would use the Bump node and it also has a Strength adjustment. NormalMap is if you already have a normal map as your image and want to alter it.)

With a height map (i.e., the input to Bump or Displacement), the brightness of each pixel indicates how high that point should stick out. For displacement it actually sticks out, for bump it basically figures out the angle the surface would be at if the point was actually raised by that much (but doesn't actually raise it). So, if you lower the strength on that bump or normal, it just makes it stick out less. Easy.

With a normal map, the color of each pixel encodes what direction the surface at that point should be facing. If you just lower those values, I think it's going to end up changing the direction they face, which is not necessarily the same as making them closer to parallel with the object surface (which is what lowering the height would do). So, yeah, leaving the strength as 1 makes sense.

Changing the direction the surface is pointing will change the direction light is reflected from that point. That could deflect light away from the camera so the point looks darker.

Ok, thank you - that explains why the light seems different. Seems to me that bump maps are the easier solution.