View Full Version : Select Camera for facing ratio?

08 August 2004, 05:29 AM
Hi, assuming you have at least two cameras in your Maya scene, I would like to know a way of choosing which camera is influencing the facing ratio in the samplerInfo node.



08 August 2004, 05:53 AM
The one that you render from.

08 August 2004, 07:06 AM
do you mean if you want the effect to use a different camera than the one you choose??

08 August 2004, 07:24 AM
Yes I mean I can't see a way of _choosing_ a camera for the facingRatio, as it seems to automatically choose the rendering camera. I want to use the same camera that is being used by a camera projection texture, not the rendering camera.

08 August 2004, 07:33 AM
Just use a ramp texture to control whatever you are doing then, the facing ratio function deals with angle dependency based on the rendering cameras eye, not secondary cameras.

08 August 2004, 07:51 AM
Yes but in this case I wish the facingRatio angle dependancy to be driven by a secondary camera. Is there some way of wiring this up by using the projectionCamShape node in the Hypershade? This is just a guess. I find it hard to believe that there is not a way of doing this in a program like Maya.

The reason I want to do this is to limit a camera projection texture only to the visible surfaces of the geometry receiving it. Disabling 'wrap' in the projection node does not work if perspective projections.
Another way of doing this is to place a light in the same position/orientation as the projecting camera and use the light's shadow as data for a surfaceLuminance node to determine areas that are not receiving the projection.
However it would be nice if you didn't have to create the light in order to do this. By using facingRatio and a ramp with no interpolation, then utilising this as a mask for the projection texture, the same result could be achieved.

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