Shading Node: Accessing World Normal

[garion-mail]

Hi guys,

I have a shading node that represents a terrain shader. It is intended to do a lot of texture splatting based on the terrain slope in relation to a user defined world space axis, i.e. the up axis.

In the shading node I get the view space normal from the "normalCamera". So I would like to either have the world space normal as well or the world 2 view matrix to transform the world space axis, or even the view 2 world matrix to calculate the world normal myself.

Do you guys know a way of achieving any of this?

Thanks a lot!

[garion-mail]

I must have been blind. There are a matrixEyeToWorld attribute in the SamplerInfo as well according to the documentation, so I could use this one. However, trying to do so, I find that it does not automatically bind as "normalCamera" or "pointCamera" does.

So, does anyone know how I get the matrix attribute to connect to the (current?) sampler info node?

Thanks a lot!

[joojaa]

Its not a input its a output. The sampler info makes no computation, it just apsses you to renderer cached values.

So you need to connect this matrix out toi a computation node. in this casepointMatrixMult. But unfortunately thats not a shading node so MR will not see it. So you must use vectorProduct nodes.

But theres a easier way too, to get a slope variable and you can mit all matrix calculations all you need is a dot product between up and normal camera (so you can do thsi in prerender step). this way you don't need to matrix operate on every point wich is hell of lot cheaper.

To connect more esoteroc plugs choose other and maya will prompt you with connection editor which allows you to connect lot more stuff than normally.

[garion-mail]

Yes, a would really prefer transforming the world slope axis to camera space.

I connected the perspective view camera directly, instead of erronously using the sampler info, and it works fine.

Thanks a lot Joojaa!