material that tints light ? and pattern to bump ...

[nmn]

Hi

seems my last question was so general ? or it can't be answered in few lines, anyway hope i can some infos regarding that.

but here i have few other "more specific questions"

- how would you do a material that ... when the object is thin it looks like a very light color say whitish blue, and the more the material gets thicker it gets bluer and bluer until a certain thickness where it looks completely blue, i tried achieving that with SSS with no success till now, is SSS the best way to go for such thing?

maybe it also can be done with a refractive glassy type of material with blurred refractions and attenuation ? but i don't want a glassy look in fact, coz i don't want any transparency ...

- how would you use a pattern node, that outputs a vector, as a bump map (i.e. use it as an nN input for the lighting model for example). just plug it in or is there any special in between node to transform it ?

Best Regards

Edited May 13, 2009 by nmn

[Serg]

Hi

seems my last question was so general ? or it can't be answered in few lines, anyway hope i can some infos regarding that.

but here i have few other "more specific questions"

- how would you do a material that ... when the object is thin it looks like a very light color say whitish blue, and the more the material gets thicker it gets bluer and bluer until a certain thickness where it looks completely blue, i tried achieving that with SSS with no success till now, is SSS the best way to go for such thing?

maybe it also can be done with a refractive glassy type of material with blurred refractions and attenuation ? but i don't want a glassy look in fact, coz i don't want any transparency ...

- how would you use a pattern node, that outputs a vector, as a bump map (i.e. use it as an nN input for the lighting model for example). just plug it in or is there any special in between node to transform it ?

Best Regards

Q1

The node you need is RayHit .

You need to decide what direction you want to measure thickness, but it will most likely be from the camera eye, so you plug "I" global var into the dir. You then need to remap the output with a "Fit Range" node into a useful range like 0 to 1.

You may come across the situation where rays that don't hit anything render black (as expected but not desired)... to fix this plug dist into a "Compare" node and check if the value is == -1 (-1 is the value returned when nothing is hit) then add the resulting integer value to the output of the "Fit Range" before finally plugging it into a ramp or whatever.

Q2

The provedural patterns don't output vectors useful for bump mapping. You probably want to use the float outputs and a "Displace Along Normal" node (in the context of a surface shader it acts as a bump map), then normalize N and plug into the nN

hope this helps

S

[nmn]

Hi Serg, thank you a lot for your time, and also thanks for the SSS shader you've done

so for Q2 it's clearer now :thumbsup:

as for Q1 thanks for the tips, but ... in fact maybe trying to explain the problem will me of more help :

http://img.tomshardware.com/us/2004/04/14/...ace-scatter.jpg

what i'm trying to chieve is smtg close to this but not really this, let me explain

in fact here we can see that whitish color at the nose which goes darker the more we go deeper into the head, till now evertg is ok and that's what i need (though i couldn't replicate it yet neither with your sss nor with mario's maybe because my model has some small details with strong curvatures ? )

so now to the part that isn't on this model and that i need also:

so let us for example take off the nose of this head and replace it with half a sphere (like a clown but half sphere) then make a pit in the tip of that nose with a depth ~ the radius of the sphere (as if it's a dough and you pressed on it with your finger inwards)

now that we have our model, and if it has the same material as the one in the image we expect to have all that sphere thingy and it's bottom almost whitish, WHILE in the reference images that i'm working on (not allowed to post) in such a case the outer parts of the sphere thingy will look whitish while its bottom has the same color as the dark color we see in the middle of the head !!

it's as if we have an sss object with a very small sss depth composed with an object of a big sss depth , and i tried to do that by adding together 2 sss nodes one with big one with small sss , didn't get me what i want. or could it be layered sss we need ? ... sry for talking that much trying to explain that porblem, but i tried to be as clear as possible. hope you could help me on that one ...

Thanks and best regards