The light sampling functions calculate light sampling PDF for the case that the light has been randomly selected out of all lights.
However, since BPT handles lamps and meshlights separately, this isn't the case. So, to avoid a wrong result, the code just included the 0.5 factor in the throughput.
In theory, however, the correction should be made to the sampling probability, which needs to be doubled. Now, for the regular calculation, that's no real difference since the throughput is divided by the pdf.
However, it does matter for the MIS calculation - it's unbiased both ways, but including the factor in the PDF instead of the throughput should give slightly better results.
Reviewers: sergey, brecht, dingto, juicyfruit
Differential Revision: https://developer.blender.org/D2258
We raised the minimum to GL 2.1 in Blender 2.77, and dropped support for older GPUs (pre-2012 Intel mostly). On Windows you get a popup message, but on Mac we simply crashed. Every Mac has a builtin software renderer for GL 2.1 so let's use that when the GPU is not capable!
Run blender --debug-gpu to see version detection & software fallback.
Idea here is to select the lowest isolation level that wont compromise quality.
By using the lowest level we save memory and processing time. This will also
help avoid precision issues that have been showing up from using the highest
level (T49179, T49257).
This is a pretty simple heuristic that gives ok results. There's more we could
do here, such as filtering for vertices/edges adjacent geometric features that
need isolation instead of checking them all, but the logic there could get a
bit involved.
There's potential for slight popping of edges during animation if the dice
rate is low, but I don't think this should be a problem since low dice rates
really shouldn't be used in animation anyways.
Reviewed By: brecht, sergey
Differential Revision: https://developer.blender.org/D2240
This reverts commit ecbfa31caa.
Original commit broke logic in nodes re-fitting. That area can
access non-existing children momentarely. Not sure what would
be best solution here, for now simply reverting the change/
Problem was zero length normal caused by a precision issue in patch evaluation.
This is somewhat of a quick fix, but is better than allowing possible NaNs to
occur and cause problems elsewhere.
Both spot and area light have large areas where they're not visible.
Therefore, this patch stops the light sampling code when one of these cases (outside of the spotlight cone or behind the area light) occurs, before the lamp shader is evaluated.
In the case of the area light, the solid angle sampling can also be skipped.
In a test scene with Sample All Lights and 18 Area lamps and 9 Spot lamps that all point away from the area that the camera sees, render time drops from 12sec to 5sec.
Reviewers: brecht, sergey, dingto, juicyfruit
Differential Revision: https://developer.blender.org/D2216
Small issues in GHOST
- use NSApplicationDelegate protocol for our app delegate
- make sure NSApp is initialized before using
(cherry picked from commit df7be04ca6)
The title says it all actually. From tests with barber shop scene here
gives 2-3x speedup for shader compilation on my oldie i7 machine. The
gain is mainly due to textures metadata query from jpeg files (which
seems to requite de-compression before metadata can be read). But in
theory could give nice improvements for scenes with huge node trees
as well (i'm talking about node trees of complexity of fractal which
we had reports about in the past).
Reviewers: juicyfruit, dingto, lukasstockner97, brecht
Reviewed By: brecht
Subscribers: monio, Blendify
Differential Revision: https://developer.blender.org/D2215
The issue was caused by some false-positive empty non-AABB intersection.
Tried to tweak it a bit so it does not record intersection anymore.
Hopefully will work for all platforms. Tested here on iMac and Debian.
Basically just moves cached kernels from ~/.config/blender/BLENDER_VERSION to
~/.cache/cycles/kernels. This has following benefits:
- Follows XDG specification more closely,
not as if it's totally crucial or measurable by users, but still nice.
- Prevents unexpected sizes of config folder, makes disk space used in more
predictable for users way.
- Allows to share kernels across multiple Blender versions,
which makes it easier debugging at the times close to release.
- "Copy Previous Settings" operator will no longer be copying possibly
gigabytes of cached kernels, which used to lead to really nast disk usage
and annoying delays of copying settings.
- In the future we can have some smart logic to clear old unused cached
kernels.
Currently only done for Linux and OSX. Windows still follows old "cache"
folder logic, but it's not really important for now because we don't
support kernel compilation on this platform yet.
Reviewers: dingto, juicyfruit, brecht
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2197
Constant folding was removing all nodes connected to the displacement output
if they evaluated to a constant, causing there to be no valid graph for
displacement even when there was displacement to be applied, and sometimes
caused crashes.
Using ones complement for detecting if transform has been applied was confusing
and led to several bugs. With this proper checks are made.
Also added a few transforms where they were missing, mostly affecting baking
and displacement when `P` is used in the shader (previously `P` was in the
wrong space for these shaders)
Also removed `TIME_INVALID` as this may have resulted in incorrect
transforms in some cases.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2192
Bump mapping was happening in world space while displacement happens in object
space, causing shading errors when displacement type was used with bump mapping.
To fix this the proper transforms are added to bump nodes. This is only done
for automatic bump mapping however, to avoid visual changes from other uses of
bump mapping. It would be nice to do this for all bump mapping to be consistent
but that will have to wait till we can break compatibility.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2191
The existing code uses the input value count of the first channel
for all of them. If the first channel is the largest, it leads to
a crash-causing buffer overrun in memcpy below. Likely this was
left since the time when only one channel was supported.
As a crash fix, probably should go into 2.78
This commits changes two things:
* It adds more keysyms preferably taken from XLookupKeysym than XLookupString (namely, all numpad ones).
* It falls back to keysyms from XLookupKeysym in other cases, when XLookupString does not produce anything we know of.
Finding the correct balance here is far from easy, but think we are comming rather close to it now...
Most of the time, Lamps in Cycles are just a constant emission closure, no texturing etc. Therefore, running a full shader evaluation is wasteful.
To avoid that, Cycles now detects these constant emission shaders and stores their value in the lamp data along with a flag in the shader.
Then, at runtime, if this flag is set, the lamp code just uses this value and only runs the full shader evaluation if it is neccessary.
In scenes with a lot of lamps and with "Sample all direct/indirect" enabled, this saves up to 20% of rendering time in my tests.
Reviewers: #cycles
Differential Revision: https://developer.blender.org/D2193
