Blender Git Loki

Fix for last commit, forgot changes in Cycles itself.

Fix T40609: Wrong WS between word and '?' (no space in english typography in those cases).

Cycles: Don't show "Sharp" distribution in the Anisotropic node.

Expose Weigth tools for edit mode

Most weight tools also work in edit mode.
This change exposes all applicable tools
within a separate weight tool panel
in the tools tab of the tool shelf

Reviewers: campbellbarton

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D592

Cycles: glossy and anisotropic BSDF changes

* Anisotropic BSDF now supports GGX and Beckmann distributions, Ward has been
removed because other distributions are superior.
* GGX is now the default distribution for all glossy and anisotropic nodes,
since it looks good, has low noise and is fast to evaluate.
* Ashikhmin-Shirley is now available in the Glossy BSDF.

Cycles: internal code support for anisotropic Beckmann and GGX reflection

Based on:

Understanding the Masking-Shadowing Function in Microfacet-Based BRDFs
E. Heitz, Research Report 2014

Cycles: Ashikhmin-Shirley anisotropic BSDF

* Ashikhmin-Shirley anisotropic BSDF was added as closure
* Anisotropic BSDF node now has two distributions

Reviewers: brecht, dingto

Differential Revision: https://developer.blender.org/D549

Cycles: improved importance sampling for Beckmann and GGX glossy

Samples render slower than before, but hopefully this is made up for with
reduced noise in most cases. The main slowdown comes from samples that would
previously be wasted and turn out black, which are now continued.

GGX sampling is about the same speed as before, while for Beckmann it is slower
still. Perhaps optimizations are still possible there, but didn't find anything
easy.

Code from this paper, which comes with sample code:

Importance Sampling Microfacet-Based BSDFs using the Distribution of Visible Normals.
E. Heitz and E. d'Eon, EGSR 2014

Differential Revision: https://developer.blender.org/D572

Cycles: volume sampling method can now be set per material/world.

This gives you "Multiple Importance", "Distance" and "Equiangular" choices.

What multiple importance sampling does is make things more robust to certain
types of noise at the cost of a bit more noise in cases where the individual
strategies are always better.

So if you've got a pretty dense volume that's lit from far away then distance
sampling is usually more efficient. If you've got a light inside or near the
volume then equiangular sampling is better. If you have a combination of both,
then the multiple importance sampling will be better.

Cycles: volume light sampling

* Volume multiple importace sampling support to combine equiangular and distance
sampling, for both homogeneous and heterogeneous volumes.

* Branched path "Sample All Direct Lights" and "Sample All Indirect Lights" now
apply to volumes as well as surfaces.

Implementation note:

For simplicity this is all done with decoupled ray marching, the only case we do
not use decoupled is for distance only sampling with one light sample. The
homogeneous case should still compile on the GPU because it only requires fixed
size storage, but the heterogeneous case will be trickier to get working.

Cycles code refactor: move some surface and volume path code to separate files.

Cycles code refactor: deduplicate and symmetrize some path tracing code.

Cycles code refactor: minor changes to light emission code.

Fix T40610. This is a critical bug caused by own bugfix that does not
allow editing any object type without bounding boxes.

This should be included in the final release!

Fix compilation in cycles

Code cleanup: Avoid duplicate functions for vector combination/separation in SVM.

Differential Revision: https://developer.blender.org/D597

BLI_dynstr: use function attributes and move comments into C file

UI: use BLI_strdup to store the original string.

Skin Modifier: use BLI_bitmap to tag edges

UI: uiContextActivePropertyHandle wasn't passing the event to the uiBlockHandleFunc