This gives much lower stack usage on GPU and reduces kernel memory size to
around 448MB on GTX560Ti (comparing to 652MB with previous commit and 946MB
with official release). There's also a barely measurable speedup of around
5%, but this is to be confirmed still.
At this stage we're using only ~3% for the experimental kernel and SSS
rendering seems to be faster by 40% and after some further testing we might
consider making SSS and CMJ official features and remove experimental
precompiled kernels.
The idea is to delay shooting indirect rays for the SSS sampling and
trace them after the main integration loop was finished.
This reduces GPU stack usage even further and brings it down to around
652MB (comparing to 722MB before the change and 946MB with previous
stable release).
This also solves the speed regression happened in the previous commit
and now simple SSS scene (SSS suzanne on the floor) renders in 0:50
(comparing to 1:16 with previous commit and 1:03 with official release).
This commit introduces a SSS-oriented intersection structure which is replacing
old logic of having separate arrays for just intersections and shader data and
encapsulates all the data needed for SSS evaluation.
This giver a huge stack memory saving on GPU. In own experiments it gave 25%
memory usage reduction on GTX560Ti (722MB vs. 946MB).
Unfortunately, this gave some performance loss of 20% which only happens on GPU.
This is perhaps due to different memory access pattern. Will be solved in the
future, hopefully.
Famous saying: won in memory - lost in time (which is also valid in other way
around).
This gives few percent extra memory saving for the CUDA kernel when
using regular path tracing.
Still more like an experiment, but will be handy in the future.
This commit adds the Blackman-Harris windows function as a pixel filter to Cycles. On some cases, such as wireframes or high-frequency textures,
Blackman-Harris can give subtle but noticable improvements over the Gaussian window.
Also, the gaussian window was truncated too early, which degraded quality a bit, therefore the evaluation region is now three times as wide.
To avoid artifacts caused by the wider curve, the filter table size is increased to 1024.
Reviewers: #cycles
Differential Revision: https://developer.blender.org/D1453
Previously shutter was instantly opening, staying opened for the shutter time
period of time and then instantly closing. This isn't quite how real cameras
are working, where shutter is opening with some curve. Now it is possible to
define user curve for how much shutter is opened across the sampling period
of time.
This could be used for example to make motion blur trails softer.
It was possible to miss some intersection caused by wrong barycentric
coordinates sign.
Cases when one of the coordinate is zero and other are negative was not
handled correct.
The issue was caused by non-continuous tangent space calculated for triangles.
This commit adds a Tangent input to Hair BSDF node which can be used to hook up
Tangent calculated form UV as an input to the node in order to make sure the
tangent space is continuous.
Doing this as an input instead of using default tangent layer from UV because of
several reasons:
- This way it's really easy to preserve compatibility with existing setups.
- Default UV map is not necessarily giving continuous space, one might want to
use other tangent space sources or distort the space for some artistic
decision.
Reviewers: juicyfruit, dingto
Reviewed By: dingto
Differential Revision: https://developer.blender.org/D1428
Ray direction is assumed to be normalized in such areas as scaling intersection
distance on instance push/pop when doing ray-scene intersection, but it was
possible that some closures wouldn't give normalized direction which could cause
wrong intersection checks.
Now normalization will happen on surface bounce, which could be a bit of a waste
if closure actually gives normalized direction, but currently only transparent
BSDF seems to give guaranteed normalized direction.
Issue was caused by wrong intersection distance scaling on instance pop,
which could cause intersection distance to become zero, confusing following
intersection checks.
This commit exposes the interpolation parameter for environment textures (requested by DolpheenDream on IRC), just as it already is for image textures.
Reviewers: sergey
Differential Revision: https://developer.blender.org/D1544
Issue was caused by changed function signature. This is still not really full
support of new OSL API since we don't store anything in the derivatives which
could confuse mipmapping.
So now the following OSL versions are supported (at least for compilation):
- 1.5 with closure alignment patch applied
- 1.6.8 release
- 1.7 development version from latest git
Added some extra seed to the hash, so it's now less likely to give repetitive
patters at values around zero.
This will change distribution of bricks for existing files. but it's something
inevitable.
Epsilon was quite arbitrary for GPU, replaced with checking for zero-sized faces.
It should solve both original report and the new one. After the release we can check
why GPU doesn't produce accurate math here and go to the root of the issue.
Found a way to make AVX2 CPUs happy by reshuffling instructions a bit,
so now there's no weird precision errors happening in there.
This solves some render speed regressions on CPU, but unfortunately
this doesn't help for GPU rendering.
Initial idea was to optimize calculation a bit by skipping calculation of actual
triangle edges and use vector from ray origin to triangles. In practice this
optimization didn't quite work in cases when origin point is too close to the
triangle.
Let's do 2.76 with a bit more complicated calculation, still looking into exact
reasons why watertight intersections fails in certain cases, but actual fix might
bit be ready so soon.
This fixes wrong eyes on the lady from T46013.
This isn't really complete fix, complete fix would require calculating
derivatives via OIIO API, but supporting this will either end up with
some code duplication or will require some non really safe changes at
this release cycle.
The issue was caused by uninitialized ray used for composite and AO evaluation.
Can;t really think of "proper" ray configuration here, it's all a bit arbitrary
but think initializing the ray in a way so we look at the surface in a negative
normal direction is much better alternative to uninitialized ray.
Open for alternative suggestions tho.
The issue was caused by some numeric instability in triangle intersection which
was visible on avx2 CPUs and GPUs (at least sm_20 here) but maybe some others
too.
Committing rather a workaround for now to be safe for the release, still need
some investigation.
From tests with grass field from Gooseberry project didn't see measurable
slowdown.
Fix T45769: Image Texture Node clipping bug
Simple mistakes in the normalized/pixel-space coordinates handling.
Render tests for this feature are coming.
