Blender Git Loki

Volume:
* Rename OSL closure and file to reflect recent changes.

Volume:
Cleanup and refactor of closure code in volume.h.
* Remove unused code (the brute force henyey-greenstein eval and sample function and double peaked functions). Maybe we need something here in the future, but the current code just became too confusing.

* Remove the CLOSURE_BSDF_DOUBLE_PEAKED_HENYEY_GREENSTEIN_ID, instead use CLOSURE_VOLUME_ISOTROPIC_ID now.
The final naming of the node/closure is still unsure, but better to use one consistent naming scheme. When the "g" parameter is 0, the closure is Isotropic anyway, so maybe it's ok, we'll see.

* Now we use 2 counterparts to bsdf_eval() and bsdf_sample():
volume_eval_phase() and volume_sample()

ToDo:
* Reflect these changes for OSL.

OSL implementation of the Henyey-Greenstein volume closure. A lot of cleanup included.

Volume:
* Fix some render errors (no caustics etc.), the patch accidentally removed some lines in kernel_path.h.
* Remove unused bsdf_eval_add() function.

* Put some more volume code behind __VOLUME__.
* Compiling on the GPU works and renders fine (sm_21 here), if you want to test uncomment the line in kernel_types.h.

Cycles / Volume Rendering:
* Initial and experimental implementation of volumetric rendering.

At this stage it is already usable, although there are a lot of limitations still:
- No Volume rendering in Branched Path integrator.
- No Smoke volume rendering
- No OSL support
- UI and data structures are WIP, be careful when saving files with this.
- ...

Credits:
* Based on the original patch by "storm".
* Cleanup and improvements by Stuart Broadfoot.
* A crash fix by Lukas Tönne.
Thanks a lot guys!

* Also some cleanup and refactor by myself.

Some WIP docs and infos: http://wiki.blender.org/index.php/User:DingTo/Volume

Branch maintenance:
* Revert r59183 and r57612 of my branch. Those changes were experimental. In case we need it, it's still in SVN history.
* Also fix a mismatch in gpu_shader_material.glsl.

Trunk and my branch are now equal, except splash.png. Compared with Meld, thanks to Campbell for the suggestion. :)

Merged revision(s) 59906-59929 from trunk/blender into soc-2013-dingto.

Merged revision(s) 59751-59905 from trunk/blender into soc-2013-dingto.

* Resolved a conflict in intern/cycles/render/object.cpp.

Merged revision(s) 59605-59750 from trunk/blender into soc-2013-dingto.

Merged revision(s) 59491-59602, 59604 from trunk/blender into soc-2013-dingto.

Cycles / Sky Model:
* Rename Albedo to Ground Albedo, and improve tooltip.
* Soft UI Range for Turbidity, between 1 and 10, higher values can produce weird results. I checked and other engines clamp this to 10 as well.
* Some code cleanup.

Merged revision(s) 59438-59490 from trunk/blender into soc-2013-dingto.

Merged revision(s) 59247-59437 from trunk/blender into soc-2013-dingto.

Cycles / Sky Model:
* Remove the KernelSunSky struct, which limited us to 1 Sky texture for SVM. Now we can use more than 1 Sky shader, which allows some artificial effects like 2 Sun/Sky's or so.

* New and old model are now working in OSL as well.

Patch by Lukas Tönne, with some small tweaks by me. Thanks!

ToDo:
* Code cleanup!

Merged revision(s) 59185-59246 from trunk/blender into soc-2013-dingto.

Cycles / Sky Model:
* Old and new model can now be selected from a drop down menu.
* Old blend files load fine and use the old model, when we create a new Sky Texture node it defaults to the new model.

* Fixed Strength issues with new model and some code cleanup there.

ToDo:
* OSL implementation for thee new model.
* Code cleanup. Maybe outsource the whole precalc into its own cpp file?