Hi
I’m trying to figure out this problem. Say, I want a material that has a generic, subtle bump on its surface (e.q. for rust or whatever). And also an engraved text, that is way deeper. I mean order of magnitude deeper. Something like below:
Now, the way I achieved that is by connecting the “rust” texture into the Normal input of the shader. Since it is the only Normal input, I shoved the “Text” texture right into the Displacement input of the Material output ( see below).
That does not seem right.
There must be something obvious I’m missing.
Question #1:
What is the “right” way to do this? Combine the textrures into one? Some other way?
Question #2:
How to make the engravement even deeper? I know it’s just a bumpmap and it has its limitations, but I believe it is possible to achieve better results without having to change the geometry.
That is its limitation. It doesn’t simulate depth at all. The only way to give it the appearance that the face sits deeper is to blur the edge so that the angle “goes deeper”. Your linear ramp isn’t doing anything, except maybe clipping the input. I tend to preview bump effects using microdisplacement and adaptive subdivision to check my values. I’m always using bump strength 1 but adjust the bump distance instead. Rust 0.001, engravement maybe 0.005?
Since we don’t have shadow masking or even disturbance factor in Cycles, our options are limited to:
Use proper displacement, at least for the engravement in this case.
Blur the edge of engravement map. Set to Cubic, may use 16 bit in some cases.
Reduce the specular in the engravement. Helps mimicking it sitting “more in shadow”, helping to indicate depth. More complex shadows can be faux’ed for a single light source.
Feed the normal input of the bump node with the image texture. Use a normal map in between if the image is a normal. In order to just mix 2 dif bump maps use 2 bump nodes and combine them with a color mix.
Hi
Thank you both for the usefull answers. I did some googling as well and turns out the texture I’ve been using wasn’t the best indeed. I applied slight gaussian blur and got much closer to th desired result
There is some weirdnes on “the bottom” of the letters, but that’s due to the texture as well.
So far I’ve been mixing just textures ( or shaders) and feed the result somewhere. Mixing bump nodes directly is a great idea. It’s weird, because of “incompatible” types (bump outputs Normal, Mix RGB inputs Colour), but it does the trick and even lets me set the strength of both inputs independently.
