View Full Version : Geometry shaders

01 January 2006, 08:24 AM
I am looking for some tutorials for using geometry shader in mentalray...
Could someone plaese help me.


Ian Jones
01 January 2006, 09:28 AM
MR Shaders can vary from software to software... which are you using?

01 January 2006, 08:19 AM
Hai Thanks for replying..
I am using maya 7 and mentalray

01 January 2006, 01:58 PM
here's a basic example:
1. create a locator (or any other node that has a transform node attached - ie polyCube, etc), then open it's AttributeEditor and in the transform tab, under the mentalray section, click the Geometry Shader checkbox to enable. Usually you would now press the un-dimmed map-button, but there seems to be some problems with the mib_geo nodes... so go to step 2 :)
2. create a mib_geo_cone node (from the Geometry section of the Create Render Node Window) then with the Connection Editor plug mib_geo_cone1.message into locator1.mentalrayControls.miGeoShader.

now render and watch how the locator gets rendered as a cone :D

yes this is a very basic example that i don't think you'd ever need to do, but the geo shader can be used for many other tasks (hair_geo, light_geo, etc)

01 January 2006, 07:58 AM
hai yashu!
Thanks for ur help.
I tried following ur tips.
When i connect the shader to the locater .... the render is showing nothing.
INstead if i connect the shader to any renderable geometries transform node it is happening.
Do u know why..


04 April 2006, 10:13 AM
connectAttr -force mib_geo_cone1.message |pCube1.message;

// Error: The attribute 'pCube1.message' cannot be connected to 'mib_geo_cone1.message'. //

"connectWindowWith mib_geo_cone1.message pCube1.message";

that what I have when I try your exemple. Explain more please

04 April 2006, 10:55 AM
yep that's the problem i was talking about... the map button points to pCube1.message instead of pCube1.mentalRayControls.miGeoShader... wierd bug of maya 7 :shrug:

so to fix that, after you press the map button, in the create render node window, don't press the mib_geo_cone icon-button, but drag it with the MMB and drop it on the "Geometry Shader" slot.

And indeed, it doesn't work on a locator... probably because locators aren't renderable and don't get exported by the mayatomr translator


04 April 2006, 02:14 PM
that bug is fixed in 7.0.1


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