* Non-Progressive integrator is now available on the GPU (CUDA, sm_20 and above).
Implementation details:
* kernel_path_trace() has been split up into two functions:
kernel_path_trace_non_progressive() and kernel_path_trace_progressive().
* We compile two CUDA kernel entry functions (in kernel.cu) for the two integrators, they are still inside one .cubin file but due to the kernel separation there should be no performance problem. I tested with the BMW file on my Geforce 540M and the render times were the same for 100 samples (1.57 min in my case).
This is part of my GSoC project, SVN merge of r59032 + manual merge of UI changes for this from my branch.
* Code refactor to split the GPU kernel into two, one for each integrator.
This way we can enable Non-Progressive integrator on GPU in trunk without a performance drop.
Thanks to Brecht for some help and review!
for texture system in advance. Patch by Martijn Berger, with some tweaks.
There was about a 10% performance improvement on OS X in my tests with the
images.blend test file. This may be less on other platforms because OS X has
particularly slow mutex locks.
* Render Passes are now available for Subsurface Scattering (Direct, Indirect and Color pass).
This is part of my GSoC project, SVN merge of r58587, r58828 and r58835.
* Added a node to convert a temperature in Kelvin to an RGB color. This can be used e.g. for lights, to easily find the right color temperature.
= Some common temperatures =
Candle light: 1500 Kelvin
Sunset/Sunrise: 1850 Kelvin
Studio lamps: 3200 Kelvin
Horizon daylight: 5000 Kelvin
Documentation: http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/More#Blackbody
Thanks to Philipp Oeser (lichtwerk), who essentially contributed to this with a patch! :)
This is part of my GSoC 2013 project. SVN merge of r57424, r57487, r57507, r57525, r58253 and r58774
* Added a Ray Depth output to the Light Path node, which gives the user access to the current bounce.
This can be used to limit the maximum ray bounce on a per shader basis. Another use case is to restrict light influence with this, to have a lamp only contribute to the direct lighting.
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/More#Light_Path
This is part of my GSoC 2013 project. SVN merge of r58091 and r58772 from soc-2013-dingto.
* Code cleanup to avoid duplicated enum code.
* Added a third type for conversion next to Point and Vector: Normal. This is basically the same result as with the Vector type, but normalizes the vector at the end.
Thanks to Brecht for code review!
* Fix some things which came up in code review. Includes some fixes for background lights and changes to variables, to avoid some castings.
Thanks to Brecht for code review! :)
* Avoid check for !LABEL_TRANSPARENT in "kernel_path_non_progressive_lighting", transparency is either handled in the outer loop or in the "kernel_path_indirect" function, but not here.
* Increase the maximum amount of closures per shader from 16 to 64, so more complex closure trees can be rendered.
I measured performance on CPU and GPU (Geforce 540M) and couldn't find a performance impact, but if someone encounters a noticeable impact on his system, please report.
* First step toward Subsurface Scattering render passes (Color, Direct and Indirect).
* Added UI, DNA and RNA for the new Passes on the Blender side.
* Basic Cycles integration.
* Only the SSS Color Pass works so far.
ToDo: Direct and Indirect Pass.
Should "subsurface" be a part of BsdfEval and "path_subsurface" of PathRadiance or is that the wrong way? Should it be integrated more like the AO render pass? Some input from Brecht or Stuart would be nice. :)
* Fix the weird results with 800-804.3 Kelvin in SVM. This was an offset issue with the lookup table, made the table slightly larger now (from 954 to 956) which gives a small gap between the R/G/B components.
* Use Luminance also for values below 800 Kelvin, for consistency.
* Added a Ray Depth output to the Light Path node, which returns the current ray bounce (0, 1, 2, 3...)
* This can be used to use different shaders for direct and indirect lighting and artificial effects.
Examples:
* http://www.pasteall.org/pic/show.php?id=55158 Here we use the output to apply a different shader to the third bounce. As in this example, you can use Math Nodes (Greater Than / Less Than) if you want to use values outside of the 0/1 range.
* http://www.pasteall.org/pic/show.php?id=55159 Here we restrict the maximum bounce on a per shader basis for the left sphere. This way it looks like we would only have 1 max bounce set in the scene "Light paths" panel.
This can be used to e.g. improve performance for objects far from the camera, which do not need full GI.
Technical notes:
* Implemented for both integrators and SVM/OSL.
* This is done by passing state.bounce to the shader_setup_from_* functions.
* Note: We don't pass state.bounce to kernel_shader_evaluate() and therefore shader_setup_from_displacement() method doesn't set the value, this is outside the path trace loop. Maybe a ToDo?
* After some more thinking, solved the remaining ToDos. :)
* Added is_object check to check if we have a valid object.
* If we operate on the world, and try to convert from/to object space, we now assume world space instead, same as OSL.
* Implementation of the node for SVM. This covers all possible transformations: World <> Object <> Camera space.
As far as I can tell, it also works fine with Motion Blur enabled.
ToDo:
* SVM differs from OSL, when the node is used on the world.
* Reshuffle SSE #ifdefs to try to avoid compilation errors enabling SSE on 32 bit.
* Remove CUDA kernel launch size exception on Mac, is not needed.
* Make OSL file compilation quiet like c/cpp files.
