Are you a Maya user looking to set up accurate camera projection within Maya itself? Look here...

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Are you a Maya user looking for a camera mapping tutorial? Look here... don't miss this one!

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Are you a Maya user looking for a way to do accurate camera projection in Renderman?

The trick is to set the Slim Projection manifold correctly.

First, postion an mtor coordinate system so it matches the position of the camera from which you want it to project. (You'll reference the shape name of that coordinate system in your shaders.) If you wish, you'll be able to animate the camera, while allowing the mtor coordinate system to remain in one place — an often useful technique. Alternatively, the coordinate system could be parented under another a second immobile camera.

Let's begin:

Create a standard Planar-Z projection using a Slim shader.

Enable the "Planar Z Perp" projection type from the pulldown menu.

In "field of view" enter the camera's FOV, divided by 2.

Disable "Planar for Textures"

Use these "post projection" settings:

S repeats "- 0.5"
T repeats "- 0.5"
S offset "0.5"
T offset "0.5"

Make sure a "Surface Point" manifold is connected with the mtor coordinate system shape name referenced. Typically this will involve the expression, [coordsys mtorCoordSysShape]

This sets all the transforms that are required for correct camera projection.