[Bf-committers] OSL Composite Node

[Ton Roosendaal]

Hi,

I would also sugges to first stick to pixel operations.

A good use case would be to allow relighting, based on getting inverse view transforms from RenderLayers, so you can map (x,y + z) pixel coordinate to 3d. Add to that UV and Normal and you can go!

I always wanted to add this transform matrix to renderlayers and openEXR files... or was this done already?

-Ton-

------------------------------------------------------------------------
Ton Roosendaal  Blender Foundation   ton at blender.org    www.blender.org
Blender Institute   Entrepotdok 57A  1018AD Amsterdam   The Netherlands

On 9 Jan, 2013, at 1:32, Dan Eicher wrote:

> On Tue, Jan 8, 2013 at 4:32 PM, Brecht Van Lommel <
> brechtvanlommel at pandora.be> wrote:
> 
>> As I understand it, libjit doesn't actually come with any language
>> compiler, it's just a way to generate instructions manually. So I'm
>> not sure how using that would be trivial, LLVM gives you the same
>> functionality as libjit, but the actual implementation of OSL on top
>> of LLVM is still a lot of code?
>> 
>> 
> Yeah, one would have write a parser to use libjit, not too terribly hard
> but...
> 
> What I really meant was a way to call the compiled functions which it seems
> is basically what OSL::ShadingContext is, a wrapper around the llvm
> function calling mechanism with extra stuff tacked on for OSL globals and
> whatnot.
> 
> 
>> If you're going to allow only basic pixel processors, i.e. just
>> reading and writing to pixels in the same location then it fits quite
>> well already. You can have basic input/output parameters of shaders
>> and it could run for each pixel.
>> 
>> If you want to do things like blurring it gets more complicated
>> because there is no concept of image buffers to read/write to, so some
>> sort of mechanism for that would need to be implemented.
>> 
> 
>> From the IRC discussion it was decided not to do any complex things like
> blurs since there's no guarantee that the pixels you want to look up
> actually exist due to the way the compositor works with multi-threading and
> tiles. So just simple single pixel stuff like relighting a scene (Ton's
> example), technicolor, film-grain (I guess would work?) &etc.
> 
> Dan
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