Issue was caused by MSVC not being able to optimize some code out in the same
way as GCC/Clang does, so now that parts of code are explicitly unfolded in
order to help compilers out.
This makes speed loss much less drastic on my laptop. That's probably as good
as we can do with MSVC without investing infinite amount of time looking trying
to workaround the optimizer.
Originally we thought it's needed in order to distinguish builtin file from
filename which starts with '@', but the filepath is actually full path there
and it's unlikely to have file system where '@' is a proper root character.
Surprisingly this does not give visible speed differences, but it's still
nice to get rid of redundant check.
Our own implementation is in fact the same performance as in fast_math from
OpenShadingLanguage, but implementation from fast_math is using explicit madd
function, which increases chance of compiler deciding to use intrinsics.
This patch is based on some work done in D788 and re-formulation from Beckmann
implementation in OpenShadingLanguage.
Skipping texture lookup helps a lot on GPUs where it's more expensive to access
texture memory than to do some extra calculation in threads.
CPU code still uses lookup-table based approach since this seems to be still
faster (at least on computers i've got access to).
This change gives about 2% speedup on BMW scene with GTX560TI.
It did not preserve stratification too well and lookup-table approach was
working much better. There are now also some more interesting forumlation
from Wenzel and OpenShadingLanguage which should work better than old code.
This argument was unused and got nicely optimized out. But once it
starts to be using registers are getting stressed really crazy,
causing slow down of render.
It's not that bad because this typo could only caused not really
efficient BVH traversal, causing higher render times. Not as if
it was causing render artifacts.
This inconsistency drove me totally crazy, it's really confusing
when it's inconsistent especially when you work on both Cycles and
Blender sides.
Shouldn;t cause merge PITA, it's whitespace changes only, Git should
be able to merge it nicely.
Issue was caused by accident in c8a9a56 which not only disabled glossy
reflection if Glossy visibility is disabled, but also Diffuse reflection.
Quite safe and should go to final release branch.
Issue was introduced in 01ee21f where i didn't notice *_setup()
function only doing partial initialization, and some of parameters
are expected to be initialized by callee function.
This was hitting only some setups, so tests with benchmark scenes
didn't unleash issues. Now it should all be fine.
This is to go to the 2.74 branch and we actually might re-AHOY.
Fix T44007: Cycles Volumetrics: block artifacts with overlapping volumes
The issue was caused by uninitialized parameters of some closures, which
lead to unpredictable behavior of shader_merge_closures().
The fix was really flacky, in terms during speed benchmarks i had
abort() in the fallback block to be sure it never runs in production
scenes, but that affected on the optimization as well. Without this
abort there's quite bad slowdown of 5-7% on the renders even tho
the Pleucker fallback was never run.
This is all weird and for now reverting the change which affects on
all the production scenes and will look into alternative fixes for
the original issue with precision loss on huge planes.
This reverts commit 9489205c5c.
This merges consecutive empty steps in the decoupled record function,
which can lead to fewer iterations in the scatter functions.
Only helps slightly though (1%), but doesn't hurt to have this.
Differential Revision: https://developer.blender.org/D873
The issue was caused by numerical instability whrn having ray origin close to a huge
triangle, which could have aused bad ray distance check.
Watertight Woop intersection isn't really addressing such cases, it's dealing with
small triangles far away from the ray origin instead, so it's a bit tricky yo make
it working reliably.
While we're quite close to the release it's safer to do check in Pleaucker coordinates
if ray close to a huge triangle. Likely this additional check combined with some other
tweaks to the code doesn't cause measurable slowdown in the scenes tested here.
After the release we can play a bit more with this code in order to make it more
stable without Pleucker fallback.
Seems it's just another issue with the compiler, worked around by explicitly
telling not to inline some function.
In theory we can unify this with CPU, but we're quite close to the release
so better be safe than sorry.
The following commits were supposed to add anti-alias and help with OSL
baking:
7b16fda3791b92dfa961
However they introduced other issues (artifacts mostly), see T43550 .
Leaving the code ifdef'ed for now.
This attribute missed derivatives calculation.
Not totally sure what's the proper approach for algebraic derivative
calculation, so calculating them by definition. This isn't fastest
way to do it in this case and could be replaced with some smarter magic
in the wireframe calculation loop.
At least currently implemented approach is better than nothing.
It was complaining about explicit __constant to __private memory conversion,
which is now worked around using implicit conversion.
It's not a real fix i'm afraid and i'm still failing to build OpenCL kernel
with latest Linux drivers, but maybe it'll let someone else to investigate
what causes compiler to run out of memory?
Issue was caused by the changes in 7b16fda which changed the initial
state for rng. This commit makes it so the same initial hash is used
(which solves the regression without distorting AA-looking image.
It also makes it so OpenCL compiler is happy about this code (before
this change it'll complain about trying to cast private variable to
global one).
OpenCL doesn't let you to get address of vector components, which
is kinda annoying. On the other hand, maybe now compiler will have
more chances to optimize something out.
It could have happened with really long rays and small steps.
Step size will be adjusted to the clamped number of steps in order
to preserve render result compatibility as much as possible.
We should probably reformulate this a bit, so it will give the
same looking results without step tweaks. But this new behavior
should already be much better that it was before.
