Changes from microdisplacement work broke previous support for subdivision
meshes, sometimes leading to crashes; this makes things work again. Files
that contain "patch" nodes will need to be updated to use meshes instead, as
specifying patches was both inefficient and completely unsupported by the new
subdivision code.
Kernels can now be built without patch evaluation when not needed by the
scene (Catmull-Clark subdivision not in use), giving a performance boost
for some devices.
This way OpenCL devices can also benefit from a smaller memory footprint, when using e.g. bumpmaps (greyscale, 1 channel).
Additional target for my GSoC 2016.
Now we have the 4 component ones first (float4, byte4, half4) followed by the 1 component ones (float, byte, half).
Makes code a bit more consistent and also reduces code a bit when enabling half support on GPU in next commit.
This also exposed a typo in half CPU images for 3D textures, which wasn't used yet, but good to have that one fixed anyway.
Enables Catmull-Clark subdivision meshes with support for creases and attribute
subdivision. Still waiting on OpenSubdiv to fully support face varying
interpolation for subdividing uv coordinates tho. Also there may be some
inconsistencies with Blender's subdivision which will be resolved at a
later time.
Code for reading patch tables and creating patch maps is borrowed
from OpenSubdiv.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2111
Adds a descriptor for attributes that can easily be passed around and extended
to contain more data. Will be used for attributes on subdivision meshes.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2110
This changes actually lead to 2x slowdown. It's getting a bit annoying
because those are the changes to make pre-maxwell cards render with the
same speed.
All the changes are mainly giving explicit tips on inlining functions,
so they match how inlining worked with previous toolkit.
This make kernel compiled by CUDA 8 render in average with same speed
as previous kernels. Some scenes are somewhat faster, some of them are
somewhat slower. But slowdown is within 1% so far.
On a positive side it allows us to enable newer generation cards on
buildbots (so GTX 10x0 will be officially supported soon).
These are complex nodes, and it's conceivable they may end up constant
in some circumstances within node groups, so folding support is useful.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2084
This adds support for ngons and attributes on subdivision meshes. Ngons are
needed for proper attribute interpolation as well as correct Catmull-Clark
subdivision. Several changes are made to achieve this:
- new primitive `SubdFace` added to `Mesh`
- 3 more textures are used to store info on patches from subd meshes
- Blender export uses loop interface instead of tessface for subd meshes
- `Attribute` class is updated with a simplified way to pass primitive counts
around and to support ngons.
- extra points for ngons are generated for O(1) attribute interpolation
- curves are temporally disabled on subd meshes to avoid various bugs with
implementation
- old unneeded code is removed from `subd/`
- various fixes and improvements
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2108
While they prevent legit write past the array boundary error
those fixes introduced regression in behavior when having exact
max_hits transparent intersections and nothing else.
Previous code would have considered such case a totally opaque,
but it's not correct.
Fixes T48941: Some materials don't get transparent shadows anymore
In the triangle intersection refinement code, rays that are parallel to the triangle caused a divide by zero.
These rays might initially hit the triangle due to the watertight intersection test, but are very rare - therefore, just skipping the refinement for them works fine.
Also, a few remaining issues in the MultiGGX code are fixed that were caused by rays parallel to the surface (which happened more often there due to smooth shading).
The issue was caused by SSS intersection code gathering all
intersections without check for duplicated ones. This caused
situations when same intersection will be recorded twice in
the case if triangle is shared by several BVH nodes.
Usually this is handled by checking intersection distance
after sorting intersections (in shadow_blocked for example)
but for SSS we don't do such sorting and using number of
intersections to calculate various things.
Didn't find anything smarter than to check intersection
distance in triangle_intersect_subsurface().
This solves render artifacts in the cost of 1.5% slowdown
of extreme case rendering (SSS object filling in whole
FullHD screen).
Reviewers: brecht
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2105
- In fresnel_dielectric, the differentials calculation sometimes divided by zero.
- When the normal map was (0.5, 0.5, 0.5), the code would try to normalize a zero vector. Now, it just uses the regular normal as a fallback.
- The approximate error function used in Beckmann sampling sometimes overflowed to inf while calculating r^16. The final value is 1 - 1/r^16, however,
so now it just returns 1 if the computation would overflow otherwise.
Also, this fixes a numerical issue where A would be inf.
Since later G is set to 1 if A is larger than 1.6, the code now checks the reciprocal of A for being smaller than 1/1.6 - same effect, but no inf involved.
