around the volume.
We generate a tight mesh around the active voxels of the volume in order
to effectively skip empty space, and start volume ray marching as close
to interesting volume data as possible. See code comments for details on
how the mesh generation algorithm works.
This gives up to 2x speedups in some scenes.
Reviewed by: brecht, dingto
Reviewers: #cycles
Subscribers: lvxejay, jtheninja, brecht
Differential Revision: https://developer.blender.org/D3038
Similar to the Principled BSDF, this should make it easier to set up volume
materials. Smoke and fire can be rendererd with just a single principled
volume node, the appropriate attributes will be used when available. The node
also works for simpler homogeneous volumes like water or mist.
Differential Revision: https://developer.blender.org/D3033
This is like the only way to add variety to hair which is created
using simple children. Used here for the hair.
Maybe not ideal, but the time will show.
It is basically brute force volume scattering within the mesh, but part
of the SSS code for faster performance. The main difference with actual
volume scattering is that we assume the boundaries are diffuse and that
all lighting is coming through this boundary from outside the volume.
This gives much more accurate results for thin features and low density.
Some challenges remain however:
* Significantly more noisy than BSSRDF. Adding Dwivedi sampling may help
here, but it's unclear still how much it helps in real world cases.
* Due to this being a volumetric method, geometry like eyes or mouth can
darken the skin on the outside. We may be able to reduce this effect,
or users can compensate for it by reducing the scattering radius in
such areas.
* Sharp corners are quite bright. This matches actual volume rendering
and results in some other renderers, but maybe not so much real world
objects.
Differential Revision: https://developer.blender.org/D3054
This adds midlevel and object/world space for displacement, and a
vector displacement node with tangent/object/world space, midlevel
and scale.
Note that tangent space vector displacement still is not exactly
compatible with maps created by other software, this will require
changes to the tangent computation.
Differential Revision: https://developer.blender.org/D1734
This was disabled to avoid updating the geometry every time when the
material includes displacement, because there was no way to distinguish
between surface shader and displacement updates.
As a solution, we now compute an MD5 hash of the nodes linked to the
displacement socket, and only update the mesh if that changes.
Differential Revision: https://developer.blender.org/D3018
Previously only scalar displacement along the normal was supported,
now displacement can go in any direction. For backwards compatibility,
a Displacement node will be automatically inserted in existing files.
This will make it possible to support vector displacement maps in the
future. It's already possible to use them to some extent, but requires
a manual shader node setup. For tangent space maps the right tangent
may also not be available yet, depends on the map.
Differential Revision: https://developer.blender.org/D3015
This converts object space height to world space displacement, to be
linked to the new vector displacement material output.
Differential Revision: https://developer.blender.org/D3015
This was we can introduce other types of BVH, for example, wider ones, without
causing too much mess around boolean flags.
Thoughs:
- Ideally device info should probably return bitflag of what BVH types it
supports.
It is possible to implement based on simple logic in device/ and mesh.cpp,
rest of the changes will stay the same.
- Not happy with workarounds in util_debug and duplicated enum in kernel.
Maybe enbum should be stores in kernel, but then it's kind of weird to include
kernel types from utils. Soudns some cyclkic dependency.
Reviewers: brecht, maxim_d33
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D3011
This can be enabled in the Film panel, with an option to control the
transmisison roughness below which glass becomes transparent.
Differential Revision: https://developer.blender.org/D2904
The offscreen dicing scale helps to significantly reduce memory usage,
by reducing the dicing rate for objects the further they are outside of
the camera view.
The dicing camera can be specified now, to keep the geometry fixed and
avoid crawling artifacts in animation. It is also useful for debugging,
to see the tesselation from a different camera location.
Differential Revision: https://developer.blender.org/D2891
We can not store pointers to elements of collection property in the
case we modify that collection. This is like storing pointers to
elements of array before calling realloc().
No color pass because it's hard to define what to use as color in a volume.
Reviewers: sergey, brecht
Differential Revision: https://developer.blender.org/D2903
The algorithm averages normals from nearby surfaces. It uses the same
sampling strategy as BSSRDFs, casting rays along the normal and two
orthogonal axes, and combining the samples with MIS.
The main concern here is that we are introducing raytracing inside
shader evaluation, which could be quite bad for GPU performance and
stack memory usage. In practice it doesn't seem so bad though.
Note that using this feature can easily slow down renders 20%, and
that if you care about performance then it's better to use a bevel
modifier. Mainly this is useful for baking, and for cases where the
mesh topology makes it difficult for the bevel modifier to work well.
Differential Revision: https://developer.blender.org/D2803
The idea is to make it possible to report extra meta data from
render engine to the file writing. This way we can provide
additional information such as number of samples rendered by
resumable Cycles rendering so we can easily combine files back.
Currently only report number of samples from Cycles when rendering
a single render-layer scene. This is something what was required
here at the studio. We can easily extend that further.
Ideally we would also need to support non-string metadata, but
that's for later.
Reviewers: mont29, campbellbarton
Reviewed By: mont29, campbellbarton
Subscribers: sybren, candreacchio
Differential Revision: https://developer.blender.org/D2502
We are already using the AO distance, so might as well offer this extra
control over the intensity. Useful when an interior scene is supposed to
be significantly darker than the background shader.
Progressive refine undoes memory saving from save buffers, so enabling
both does not make much sense. Previously enabling progressive refine
would disable denoising, but it should be the other way around since
denoise actually affects the render result.
Includes some code refactor for progressive refine render buffers, and
avoids recomputing tiles for each progressive sample.
CPU rendering will be restricted to a BVH2, which is not ideal for raytracing
performance but can be shared with the GPU. Decoupled volume shading will be
disabled to match GPU volume sampling.
The number of CPU rendering threads is reduced to leave one core dedicated to
each GPU. Viewport rendering will also only use GPU rendering still. So along
with the BVH2 usage, perfect scaling should not be expected.
Go to User Preferences > System to enable the CPU to render alongside the GPU.
Differential Revision: https://developer.blender.org/D2873
This patch goes away form using C++ RNA during tangent space calculation which
avoids quite a bit of overhead. Now all calculation is done using data which
already exists in ccl::Mesh. This means, tangent space is now calculated from
triangles, which doesn't seem to be any different (at least as far as regression
tests are concerned).
One of the positive sides is that this change makes it possible to move tangent
space calculation from blender/ to render/ so we will have Cycles standalone
supporting tangent space.
Reviewers: brecht, lukasstockner97, campbellbarton
Differential Revision: https://developer.blender.org/D2810
The issue here was that removing datablock from main database will poke editors
update, which includes buttons context to free users of texture. Since Cycles
will free datablocks from job thread, it might crash Blender since main thread
might be in the middle of drawing.
Solved by exposing extra arguments to bpy.data.foo.remove() which indicates
whether we want to perform ID user count and interface updates. While scripts
shouldn't be using those normally, this is the only way to allow Cycles to skip
interface update when removing datablock.
Reviewers: mont29
Reviewed By: mont29
Differential Revision: https://developer.blender.org/D2840
