Surf. Luminance, exclude shadow from object?

[rustysunshine]

Hi:)
the sampler node you're using is performed after all the light computations are done, hence it sees only one kind of shadow (but you have 2:), proper shadows and cast ones).
I'm sure that inside the rendering passes there's one with just light intensity info and without cast shadows, but I still have no idea how to get it (still learning:))!!! If you check in the standard render pass list of maya (2011) you'll find a lot of passes with and without casts, but I don't know how to use them directly in the Hypershader...

A very primitive (and surely overcomplicated) way could be to compute manually the intensity you need; i.e. you should add some nodes evaluating:

(WLP - WP) dot N

where WLP is the position of your light in world coordinates, WP is the world coordinates of each point in your surface and N is the corresponding normal. In this way you should get the standard lambert pass (perhaps you'd need a ramp to adjust the roughness and intensity) and you could replace the sampling node that sees even the cast shadows.

Or perhaps there's a way to tell maya to disable the raytraced shadows in a particular shader node; it's possible to do that for a whole object, but for a single fragment of a shader? no idea!

Hope it helps a bit:)

gui

[JasonMiller]

Thank you for your reply rustysunshine,

I've thought about using the light direction too, so I could determine where the night texture should be placed, but — as you've already hinted — compositing software has its place too. I'll go for the render passes route. As a bonus I'll also have more control over the final result that way. :D

[rustysunshine]

I still have no idea how to do this inside Hypershade without silly tricks. Anyhow, create a fake point light under your sun and parent them together and disable the shadow casting; then, create a MiaMaterial (apparently standard maya materials have more complex or hidden light linking) for the earth disabling everything except the the diffuse (no textures) and link it to the fake sun; this way you get the intensity sample you needed originally. You "just" need to unlink the fake sun to every other material you have:), what a convenient solution ah:)?

I'll try to ask around how to gain access to render passes inside HS...

guy

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