* 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! :)
* 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.
* On nvidia Kepler GPUs (sm_30 and above), there are now 145 byte images available, instead of 95.
We could extend this to about 200 if needed.
Could not test this, as I don't have a Kepler GPU, so feedback on this would be appreciated.
Thanks to Brecht for review and some fixes. :)
* Replaced the Brute Force version with a nice lookup table, this speeds it up a lot.
Patch by Philipp Oeser (lichtwerk) with some cleanup and changes by myself. Thanks!
ToDo:
* Temperature values between 800 and 804 Kelvin are wrong in SVM, check on this.
* First (brute force) implementation for SVM. This works and delivers the same result as OSL, but it's slow.
* Code inside svm_blackbody.h inspired by a patch by Philipp Oeser (#35698), thanks.
Ideas:
* Use a lookup table to perform the calculations on render/ level.
* Implement it as a RNA property only, and do the calculation like Sun/Sky precompute.
* Added a node to convert wavelength (in nanometers, from 380nm to 780nm) to RGB values. This can be useful to match real world colors easier.
* Code cleanup:
** Moved color functions (xyz and hsv) into dedicated utility files.
** Remove svm_lerp(), use interp() instead.
Documentation:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/More#Wavelength
Example render:
http://www.pasteall.org/pic/show.php?id=53202
This is part of my GSoC 2013. (revisions 57322, 57326, 57335 and 57367 from soc-2013-dingto).
* Move hsv and xyz color functions into the dedicated util files (util_color.h and node_color.h).
* svm_lerp moved into util_math.h and renamed to lerp_interp, as it's used for the wavelength node now as well.
* Added a node to convert wavelength (in nanometer, from 380nm to 780nm) to RGB values. This can be useful to match real world colors easier.
Example render:
http://www.pasteall.org/pic/show.php?id=53202
ToDo:
* Move some functions into an util file, maybe a common util_color.h or so.
* Test GPU, unfortunately sm_21 doesn't work for me yet.
* Revert r57203 (len() renaming)
There seems to be a problem with nVidia OpenCL after this and I haven't figured out the real cause yet.
Better to selectively enable native length() later, after figuring out what's wrong.
This fixes [#35612].
* Rename some math functions:
len -> length
len_squared -> length_squared
normalize_len -> normalize_length
* This way OpenCL uses its inbuilt length() function, rather than our own. The other two functions have been renamed for consistency.
* Tested CPU, CUDA and OpenCL compile, should be no functional changes.
* Cycles Mix closure could render strange effects, when the user entered a value out of the 0...1 range. This was already clamped for OSL, clamp for SVM as well.
* Some closures (Toon, Diffuse Ramp) were not assigned to a CLOSURE_IS_* define, which made them invisible on render passes.
* Westin closures had wrong type, Sheen is Diffuse, Backscatter is Glossy.
