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
We now continue transparent paths after diffuse/glossy/transmission/volume
bounces are exceeded. This avoids unexpected boundaries in volumes with
transparent boundaries. It is also required for MIS to work correctly with
transparent surfaces, as we also continue through these in shadow rays.
The main visible changes is that volumes will now be lit by the background
even at volume bounces 0, same as surfaces.
Fixes T53914 and T54103.
It seems to be useful still in cases where the particle are distributed in
a particular order or pattern, to colorize them along with that. This isn't
really well defined, but might as well avoid breaking backwards compatibility
for now.
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 patch changes the huge list of projects in visual studio into a nice tree matching the source folder structure. see D2823 for details.
Differential Revision: http://developer.blender.org/D2823
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
The displacement shared was running before particle data was copied to the
device causing bad memory access when the particle info node was used. Fix
is simply to move particle update before mesh update so the data is
available to displacement shaders.
(Altho this fixes the crash the particle info node is still mostly useless
with displacement for now...)
Adds the code to get screen size of a point in world space, which is
used for subdividing geometry to the correct level. The approximate
method of treating the point as if it were directly in front of the
camera is used, as panoramic projections can become very distorted
near the edges of an image. This should be fine for most uses.
There is also no support yet for offscreen dicing scale, though
panorama cameras are often used for rendering 360° renders anyway.
Fixes T49254.
Differential Revision: https://developer.blender.org/D2468
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
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
Goal is to reduce OpenCL kernel recompilations.
Currently viewport renders are still set to use 64 closures as this seems to
be faster and we don't want to cause a performance regression there. Needs
to be investigated.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2775
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
This causes some difference in the classroom scene, where ray visibility
tricks are used and break the MIS balance. Otherwise there doesn't seem
to be much effect, but better to use the right formulas. Problem originally
identified by Lukas.
