This is also an important mathematical operation that can be folded
if it is known that one argument is a certain constant. For colors
the operation is provided as a Gamma node.
The SVM Gamma node needs a small fix to make it follow the 0 ^ 0 == 1
rule, same as the Power node, or the Gamma node itself in OSL mode.
Reviewers: #cycles
Differential Revision: https://developer.blender.org/D2263
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
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.
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
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
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
The two SVM nodes added with e7ea1ae78c caused a slowdown on AMD cards when rendering with OpenCL, whether displacement was used or not.
In the Barcelona Pavillon scene on a RX480, this would cause a 12% slowdown.
Therefore, this commit adds a additional flag for feature-adaptive compilation so that the new SVM nodes are only enabled when they are needed (Node tree connected to the Displacement output and Displacement type set to Both).
Also, the nodes were also added to shaders when the Displacement Type was set to Bump (the default), which was unneccessary and is fixed now.
Thanks to linda2 on IRC for reporting and testing and to maiself for help with the displacement shader code.
This fix might be relevant for 2.78, but it should be tested further before including it.
Object coordinates can now be used in the displacement shader and will give
correct results, where as before bump mapping was calculated from the displace
positions and resulted in incorrect shading.
This works by evaluating the shader in two parts, first bump then surface, and
setting the shader state to match what it would be if the surface was
undisplaced for the bump shader evaluation. Currently only `P` is set as if
undisplaced, but other shader variables could be set as well, such as `I` or
`time`. Since these aren't set to anything meaningful for displacement I left
them out of this patch, we can decide what to do with them separately.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2156
Storing multiple copies of a shader was needed when the displacement method was
a mesh option and could be different for each mesh. Now that its a shader option
this is unnecessary.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2156
Meshes with Cycles subdivision were being transformed to world space leading to
normals to sometimes be calculated in that space, while they should be in
object space. Also caused dicing to happen at the wrong rate for scaled meshes.
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.
The if branches were reordered when the original patch was
committed, which broke the implicit non-NULL guarantee on link.
To prevent re-occurrence, add a couple of unit tests.
These latter can cause MSVC debug asserts if the array is empty. With C++11
we'll be able to do this for std::vector later. This hopefully fixes an assert
in the Cycles 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.
By calling `tessellate()` from the mesh manager in Cycles we can do pre/post
processing or even threaded tessellation without concerning client side code
with the details.
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.
Displacement is now a per material setting, which means old files will have to
be updated if they had used displacement. Cool side effect of this change is
material previews now show displacement.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2140
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
Currently cycles cannot correctly render motion blur for objects that appear or
disappear during the shutter window. Until that can be fixed properly, it may be
better to hide such particles rather than let them render as if they were
stationary for half of the frame.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2125
As a result of other folding simplifications it may happen that
two type conversion nodes end up directly connected. In some
cases it may be possible to then remove both. A realistic case
might be an optimized out Mix RGB node used to blend vectors.
It seems it's safe to optimize when B is a float3 type
(color, vector), and A is float3 or float.
Reviewers: #cycles, sergey
Reviewed By: #cycles, sergey
Subscribers: sergey
Differential Revision: https://developer.blender.org/D2134
Code coverage of different combinations of secondary conditions
is obviously not complete because there are so many of them, but
all main rules should be there.
The reason for CORRECT vs INVALID is that both words have the same
number of characters so calls line up, but look quite different.
Reviewers: #cycles, sergey
Reviewed By: #cycles, sergey
Subscribers: dingto, sergey, brecht
Differential Revision: https://developer.blender.org/D2130
