Re: Arbitrary derivatives


Bo Schwarzstein <bo.schw...@...>
 

Hello,

Yes, it's amazing, I did not hear the Automatic Differentiation
before, it seems like an ideal math method to handle this.

On Jan 19, 11:09 pm, Henri <henr...@...> wrote:
On 19 jan, 09:52, Bo Schwarzstein <bo.sc...@...> wrote:

Hello folks,
In specification, it sais "Arbitrary derivatives without grids or
extra shading points.", but I really confused how it works without
explicit grid. Does it like the GPU, compute the derivatives on screen
space ?
No, it does automatic differentiation.

The overall idea is that if your inputs know their derivatives ( for
instance, when raytracing a primitive, computing P, dP/dx and dP/dy is
easy )
and your shading library know how to differentiate all its operators,
you are able to maintain derivatives quantities while shading.

Look athttp://jgt.akpeters.com/papers/Piponi04/for a complete
reference.

 Hopes this helps

         Henri



Thanks.

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