This is my second post, but you cannot see my first one, because blender killed my system during editing the post
So again: I have a metallic object that’s partially rusty. The decision, where to have rust is done by a texture that is used as a stencil (a marble colorband). The rust itself is implemented as two different textures where the first does the color and the second does the rough surface by influencing the normal.
As metal usally does, this object should have an reflecting surface. This is done by an image-map i’ve rendered from a “mirrored” camera-position (an ENVMap does not seem to work with my object) which is placed as orco and has been resized and located by me in long rendering hours.
As far it works as espected.
But there’s a mistake: the mirror-effect is visible on the rusty parts too. This is nonsense of course, as rust does not refect it’s enviroment. When thinking how to get rid of this error, i though of a second stencil that should mask the mirror-texture. This stencil should be an inverted version of that, that does the rust (the more the rust, the less the faked mirror).
I tried it with the NEG-Option but this doesn’t work. So I did a new texture that is an exact inversion of the first (it was done by doing a copy of the first and inverting the color-band) but this results in a distorsion of the objects color.
It seems, it is not possible to do two different and independent stencils in one material. Is this correct?
But i have a workaround - which doesn’t work as it should too
The idea was: If i cannot prevent blender from rendering the mirror-image, it might be possible to cover the mirror with the rust completely.
But as you probably know: if you lay multiple textures over each other, the underlying ones are looking throught the ones above. Can someone tell me, how i have to configure the textures (add/mix…) to let the rust cover the mirror completely.
The textures are layered in the following order:
a texture that does som pumps to the metall by affecting the normals
(not mentioned above)
you need a pro to answer this, and as I’m astill at amateur level, i suggest playing with the Cmir and Ref buttons on the rust texture (the one affecting the normal? :-? )
I don’t understand why you use the three last slot for the same texture: one should be enaugh… and to make the env map appearing under the rustfree areas you should use alpha areas to make them transparent, so the envmap can be visible. Maybe selecting the alpha button in the marble stencils for the rust can work.
I think, that’s ne most realistic way to do the rust. With the stencil-texture i can influence the location of the rust and can do a fading from rusty to non-rusty. With the second-texture i can do the color. And the third is needed to give a look auf roughness that is independent from the color and therefore cannot be done in the colors layer.
That might be a solution if you’re using a single layer for the rust. But i don’t see a way to do a realistic rust within a single layer.
So my problem is not to make the mirror appear (because it allready is there, is everywhere), but to make it disappearing at that locations, that are rusty.
I just realized, that the covering is done if i increase the Col-Value for the rust-textures.
That sounds logical but i never tried this, because my basic impression was, that if blender lays multiple textures above each other, the underlaying textures are visible through the overlaying ones. In fact this is, because most textures allready have a partiall transparency.
So my problem is solved.
What would still be interesting to me: is it possible to use two different AND independant stencils in one material?
if you use a targa image with an alpha channel, you can use that to determine the visibility of the rust. Just save the rust image (if it isn’t procedural) with the alpha and say ‘use alpha’ in the texture buttons.
this way, you can have one sort of stencil for each texture channel