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.
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
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
It is not possible to use a set split by name as valid input to
check_node_input_traversed - it needs a complete set of all nodes visited so
far. On the other hand, the merge comparison loop should only check nodes that
were not just visited, but found unique. This means that there should really be
two separate data structures.
Without the fix, check_node_input_traversed actually never returns true, so
only nodes without any inputs are processed.
Some closures were missing from calculation, leading to an array
under-allocation, presumable causing memory corruption issues with
emission shaders on OpenCL and was causing issues with Volume 3D
textures with CUDA.
The issue was identified by Thomas Dinges, the patch is different
from the original D2006. See the brief discussion there. Current
approach is similar (or the same) as Brecht suggested.
The idea is to have separate sets per node name in order to speed up the
comparison process. This will use a bit more memory and slow down simple
shaders, but this extra memory is not so much huge and time penalty is
not really measurable (at least from initial tests).
This saves orders of magnitude seconds when de-duplicating 17K nodes and
overall process now takes 0.01sec on my laptop,
The idea of this commit is to merge nodes which has identical settings
and matching inputs into a single node in order to minimize number of
SVM instructions.
This is quite simple bottom-top graph traversal and the trickiest part
is how to compare node settings without too much trouble which seems to
be solved is quite clean way.
Still possibilities for further improvements:
- Support comparison of BSDF nodes
- Support comparison of volume nodes
- Support comparison of curve mapping/ramp nodes
Reviewers: brecht, juicyfruit, dingto
Differential Revision: https://developer.blender.org/D1673
This is actually intended behavior to return NULL when the socket is not
found. It's used in certain BSDF nodes to query whether some inputs exists
or not.
Perhaps we can be more explicit here and have dedicated logic to query
socket existance and keep assert in place.
In any case, even if we lost assert() for the constant fold now it's
still somewhat better than duplicated code. Perhaps.
This way, connecting Value or RGB node to e.g. a Math node will still allow folding.
Note: The same should be done for the ConvertNode, but I leave that for another day.
This reduces stress on the the stack memory which could be really handy
on certain operation systems which applies strict limits on the stack.
Reviewers: brecht, juicyfruit, dingto
Reviewed By: brecht, juicyfruit, dingto
Differential Revision: https://developer.blender.org/D1656
Graph::disconnect() actually modifies links, needs to create a copy to iterate
if disconnect happens form inside the loop.
Question tho whether we can control this somehow..
Reported by BzztPloink in IRC, thanks!
The issue was caused by not really optimal graph traversal for gathering nodes
dependencies which could have exponential complexity with a long tree branches
connected with multiple connections between them.
Now we optimize the depth traversal and perform early output if the node was
already traversed.
Please note that this adds some limitations to the use of SVM compiler's
find_dependencies() in the cases when skip_node is not NULL and one wants to
perform dependencies find sequentially with the same set. This doesn't happen
in the code, but one should be aware of this.
The issue was than nodes dependencies were stored as set<ShaderNode*> which
is actually a so called "strict weak ordered", meaning order of nodes in
the set is strictly defined, but based on the ShaderNode pointer. This means
that between different render invokations order of original nodes could be
different due to different pointers allocated for ShaderNode.
This commit makes it so dependencies and maps used for ShaderNodes are based
on the node->id which has much more predictable order. It's still possible
to trick the system by doing some crazy edits during viewport rendfer and
cause difference between viewport and final render stacks.
Reviewers: brecht
Reviewed By: brecht
Subscribers: LazyDodo
Differential Revision: https://developer.blender.org/D1630
Basically we can not use sharp closure as a substitude when filter glossy is
used. This is because we can not blur sharp reflection/refraction.
This is quite quick and not really clean implementation. Not really happy
with manual handling of original settings, but this is as good as we can do
in the quick patch. It's a good acknowledgment and we now can re-consider
some aspects of graph simplification to make such cases more natively
supported.
P.S. This failure would have been shown by our regression tests, so please,
bother a bit to run Cycles's test sweep before doing such optimizations.
We fallback to Sharp closures for Glossy, Glass and Refraction nodes now, in case the Roughness input is disconnected and 0 (< 1e-4f to be exact).
This way we gain a few percentages of performance, in case the user did not manually set the closure type to "Sharp" in the UI.
Sharp will probably be removed from the UI as a followup, not needed anymore with this internal optimization.
Original idea by Lukas Stockner(Differential Revision: https://developer.blender.org/D1439), code implementation by myself.
It can't be simply removed in cases when it's connected to input which is
different from Normal. This is because the input wouldn't be connected to
default Normal geometry input, possibly breaking shading setup.
The fix is not really ideal, but should work at least.
This fixes skin having too much glossy reflection in the file from T46013.
Bump result was passed to set_normal node and then set_node was connected
to all unconnected Normal inputs, including the one from original Bump
node, causing cycles.
* If a Background node is set to a black color or zero strength,
it now gets removed from the shader graph.
* In case the graph is empty (no background node), the kernel will skip
evaluating it and save some rendertime. This can help quite a bit in scenes,
where the majority of the image consists of a black background.
Example: http://www.pasteall.org/pic/show.php?id=82650
In this case the render is ~16% faster.
Differential Revision: https://developer.blender.org/D972
