I am trying to use a generated material as a texture for the backface of a complex object in Blender Internal (an object that already have a texture). The idea, using nodes, is similar to Back face cull rendering. What I want is that the material being used should look like it is projected onto the render screen of the camera.
As an example (see below), I am using a wood materials in Nodes. Even if the object has a complex shape and a texture, I would like the rays of the wood to look parallel in the render view. I thought I could use a geometry node and use one of its output, then a vector curves with the shown curves for the x, y and z coordinates to make any vector pointing towards VIEW, or use a normal node, but I could not get any result. Using a "normal" node as an input for the vector input of the texture node, I get a blank material in the texture node.
Ps : I've looked a lot in Blender reference concerning texture nodes with no clues. I would love something similar to UV unwrapping orthogonal to view, but for the backface part of the material (Noe that the object already is UV mapped since it has a texture already).
Does anyone know how I could achieve this ? The ideal would be that it could be used in Blender Internal. If you have a solution for cycles, I could also use it, but prefer the BI solution. I am aware of the Texture coordiates node in Cycles that could help me achieve what I want, but in Cycles only.
Thanks a lot for your help,