Render Tree question ...????

[JDex]

Hey Dimitris,

It's really best to not use clusters for materials... there are many downsides to it.

Some are kind of "bug" related, but the workaround infact make for some better situations. I think that clusters were not intended for shading uses, and thus are not implemented efficiently for that use.

The main problem, as I understand it, with using clusters to assign materials involves serious difficulties with partition overrides and rendering passes.

The workflow reccommended by Atyss (who generally has the scoop) is to assign materials using Mix#Colors nodes in the render tree and basic weightmaps. I have been doing this on my work since starting, and it is really very small. By following this technique, you will have all of the materials of your model available in the same render tree.

Cheers

[DimitrisLiatsos]

Hey JDex ..thanks...but here comes an issue of speed (especially when working for TV spots)...u meen that when i want to assign a new shader in a number of polygons and not on all of the object..i have to create a weight map...and what if i want to ghange some faces shading again in the object..i have to make a new weight map?...if i understood correctly of 'course...:shrug: forgive my contnuus questions

[JDex]

Well... it's really not that difficult. I perhaps should clarify that... by weightmaps I mean Grayscale Texture maps (created in PS or another 2d app), not the XSI weightmaps.

Basically, you create the object and set up the texture projections... decide what shader types you need (Phong, Blinn, etc.) add and setup the necessary parameters for those shaders, then plug into Mix2Colors (or 8) plugged into the object's root material (Surface, Photon, Shadow, etc...)

Then using your UV Stamp, paint a grayscale "weightmap". Often what I have been doing, in lieu of using textures (unless it is a complex model) is making a specific texture projection for weightmaps (or multiple if it will make things easier) then use a B>W gradient (no grays) to mix the materials. The handy part of this, is that you can then use clusters as poly selections, and on the fly adjust the UV's.

[DimitrisLiatsos]

ok then...of to testing room...thanks!!! :thumbsup:

[zen]

back to the original question, Yes xsi does gather all the cluster materials also.
When you open your rendertree, the place where the name is has a dropdown menu. If you are a clean worker and name your clusters and mats, you should have no problem finding them.

I would not suggest NEVER using clusters. There are speed issues involved in applying all your shaders in a huge tree to all your model. Its a per case type decision.

if you choose to use weight maps, I personnaly use vertex paint maps. Theyre seamless, super easy to make, ultra easy to modify at any stage during the shading process. And they weigh nothing.

[DimitrisLiatsos]

thanks zen... i must check this matter more...i never thought to go with vertex paint maps...must check this too :)

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