PDA

View Full Version : Production shaders {hidden} - problem with reflections in matteshadow shader!


ScallyFox
05-27-2010, 08:49 AM
I read everything I found about it and still can not solve this problem.
Production shaders are working great for me, doing big job and helping very much.

But! I have troubles with matteShadow shader. I cannot make correct setup, where I have more than one matteshadow shader with different attribute. Simple case -- I need one matte object to have reflection, and another with no reflection. And they must do not interact with each other (do not cast occlusion on each other) With ONE matteshadow shader it works perfectly, I put it in the shadow slot of Shading Group node. But with two or more -- it doesn't work, because objects begin to occlude each other.

Here is the pic showing the problem..

http://forums.cgsociety.org/attachment.php?attachmentid=153688&stc=1

and second problem -- almost always I use reflections in matteshadow I have a hole in alpha. How can I get rid of that?

MasterZap, if you are reading that -- help me out, please!!:))) And thank you A LOT for this shaders!

jeb
05-27-2010, 10:23 AM
You could use vertex paint on your matte geometry to paint the wall black and the floor white then use this vertex color map in the reflection color slot of the matte shadow material, that way the wall has 0 reflectivity and still use only one material for correct occlusion.

you could use any map actually .. ex:bitmap

but i rather use vertex color for cases like these so i have one map less in hard drive.
about the hole.. really no clue what could be without actually setting it up like you did.. perhaps someone else knows.. would like to know too whats causing it

ScallyFox
05-27-2010, 12:15 PM
jeb, thanks for quick reply..
you could use any map actually .. ex:bitmap
does it mean I need do texture mapping on my matte objects?
Is it possible to avoid this? I'll explore an option of vertex painting, I did not used this metod before..
Is it possible to use the painted map (on vertexes) without converting it to texture? (yes, without making correct UV map)

ScallyFox
05-27-2010, 12:26 PM
I did quick setup with UV mapped objects -- it works!:bounce::bounce:

jeb
05-27-2010, 12:48 PM
vertex paint is really awesome..

you dont just paint over vertex but can also fill polygons with solid colors..works great for masking stuff.

check the old 3ds max video tutorials from autodesk site.. there is one about vertex paint..

i mentioned vertex paint because sometimes you have your matte geometry already mapped or maybe not mapped and to avoid touching your hard worked UV map or even to avoid uvmapping something difficult you can just use vertex paint .. it saves drive memory and time.

ScallyFox
05-27-2010, 02:00 PM
yes, it's a luck that I don't have matte objects mapped with something else! Thank you for the tip:love:
Actually I'm doing this in maya, but it should some similar way to paint polygons, like in 3dmax

jeb
05-27-2010, 09:27 PM
oh i see..

hmm actually a friend of mine was trying to do the same in maya with vertex paint as in max but with no sucess.. if you find how do they work could you post it?

ScallyFox
05-28-2010, 08:27 AM
well... after some tests.. I can say that there is no way to do it in Maya:shrug:
Max users use map channel, to connect polygon painting in material atribute (transparency, color.. whatever) But in maya there is no "map channel" at all. Pity.
maybe writing an expression that will take per vertex color from object and transfer it to material could help.. But I'm not good in scripting, at all..

CGTalk Moderation
05-28-2010, 08:27 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.