Understand exactly what a projection type is ?

[fantome]

Hi guys,

I am following this great tut by Rohan Dalvi.
https://vimeo.com/172594655

But i am not perfectly understanding what exactly is the projection type outputed by the Projection UVW node.
It looks like a transform matrix.

But i am not understanding how the Texture Image use this matrix and what the matrix itself contain ?

Because in the tuts he use a simple 1D gradient. But i was wondering if by using a 2D gradient map like those,
it was possible to access to 2 channel info instead of 1?

And thus to scale the possible custom float attribute accessible in the shader from 3 to 6.

Thanks for your lights !
Cheers
Emmanuel

[fantome]

well it looks that by using this gradient , you can map both U and V.
we can access 2 channel instead of 1. But it looks that there are no way to separate channel with octane.

there aren't any vector to float and float to vector utility.
so it's not possible to extract the info.

EDIT:
After some further test it looks that having just a color to float utility will allow us to use 6 custom float attributes instead of 3.