In practice this means that if you don't connect a texture to your volume nodes
it will figure that out and render the node faster, rather than you having to
specify it manually.
Main weakness is custom OSL nodes where we have to assume it is heterogeneous
because we don't know what kind of data the node accesses.
These can currently be accessed by adding an Attribute node and specifying one
of those three names. A Smoke/Fire node should be added at some point to make
this more convenient.
These values might change still before the release, in particular for flame the
meaning seems unclear, it's just values in the 0..1 range. This is useful for
color ramps, but it might be good if this was also available as temperature in
kelvin so it can be plugged into the blackbody node. But I couldn't figure out
from the smoke code if or how this corresponds to a physical unit.
Here's a (quite poor) example file for a fire + smoke setup:
http://www.pasteall.org/blend/27990
These are internally stored as a 3D image textures, but accessible like e.g.
UV coordinates though the attribute node and getattribute().
This is convenient for rendering e.g. smoke objects where data like density is
really a property of the mesh, and it avoids having to specify the smoke object
in a texture node, instead the material will work with any smoke domain.
This now supports multiple steps and subframe sampling of motion.
There is one difference for object and camera transform motion blur. It still
only supports two steps there, but the transforms are now sampled at subframe
times instead of the previous and next frame and then interpolated/extrapolated.
This will give different render results in some cases but it's more accurate.
Part of the code is from the summer of code project by Gavin Howard, but it has
been significantly rewritten and extended.
added in rB74518b28267e9b18199212fbaa3c689fa018d20c.
No special bind/unbind needed for standalone viewer, so can just use a
static stub in the display callback.
Issue was caused by the wrong usage of OCIO GLSL binding API. To make it
work properly on pre-GLSL-1.3 drivers shader is to be enabled after the
texture is binded to the opengl context. Otherwise it wouldn't know the
proper texture size.
This is actually a regression in 2.70 and to be ported to 'a'.
This adds a new option "Sample All Lights" to the Sampling panel in Cycles (Branched Path). When enabled, Cycles will sample all the lights in the scene for the indirect samples, instead of randomly picking one. This is already happening for direct samples, now you can optionally enable it for indirect.
Example file and renders:
Blend file: http://www.pasteall.org/blend/27411
Random: http://www.pasteall.org/pic/show.php?id=68033
All: http://www.pasteall.org/pic/show.php?id=68034
Sampling all lights is a bit slower, but there is less variance, so it should help in situations with many lights.
Patch by myself with some tweaks by Brecht.
Differential Revision: https://developer.blender.org/D391
All textures are sampled bi-linear currently with the exception of OSL there texture sampling is fixed and set to smart bi-cubic.
This patch adds user control to this setting.
Added:
- bits to DNA / RNA in the form of an enum for supporting multiple interpolations types
- changes to the image texture node drawing code ( add enum)
- to ImageManager (this needs to know to allocate second texture when interpolation type is different)
- to node compiler (pass on interpolation type)
- to device tex_alloc this also needs to get the concept of multiple interpolation types
- implementation for doing non interpolated lookup for cuda and cpu
- implementation where we pass this along to osl ( this makes OSL also do linear untill I add smartcubic to the interface / DNA/ RNA)
Reviewers: brecht, dingto
Reviewed By: brecht
CC: dingto, venomgfx
Differential Revision: https://developer.blender.org/D317
Problem is that the particle systems in the cycles database are not
stored in a well-defined order. This means the particle_id for dupli
objects can not simply be assigned using a global running index during
sync.
Now the particle index is assigned locally for each particle system.
When transferring particle data to the device as a single texture, the
particle indices are offset based on the final order of particle systems
in the database.
Reviewers: brecht
Reviewed By: brecht
CC: Andreas80
Differential Revision: https://developer.blender.org/D352
This adds an option in the Volume Sampling panel, which helps rendering lamps
inside or near volumes with less noise. It can also increase noise though and
needs improvements to support MIS and heterogeneous volumes, but since it's
useful in some cases already (especially world volumes) it's there now.
Based on the code in the old branch by Stuart, with modifications by Thomas
and Brecht.
Differential Revision: https://developer.blender.org/D291
Indirect and Direct samples can now be clamped individually. This way we can clamp the indirect samples (fireflies), while keeping the direct highlights.
Example render: http://www.pasteall.org/pic/show.php?id=66586
WARNING: This breaks backwards compatibility. If you had Clamping enabled in an old file, you must re-enable either Direct/Indirect clamping or both again.
Reviewed by: brecht
Differential Revision: https://developer.blender.org/D303
Z, Index, normal, UV and vector passes are only affected by surfaces with alpha
transparency equal to or higher than this threshold. With value 0.0 the first
surface hit will always write to these passes, regardless of transparency. With
higher values surfaces that are mostly transparent can be skipped until an opaque
surface is encountered.
This should be pretty rare, the shader in question had many parallel node links
because of copying the nodes many times, which is inefficient to run anyway.
This is done by adding a Volume Scatter node. In many cases you will want to
add together a Volume Absorption and Volume Scatter node with the same color
and density to get the expected results.
This should work with branched path tracing, mixing closures, overlapping
volumes, etc. However there's still various optimizations needed for sampling.
The main missing thing from the volume branch is the equiangular sampling for
homogeneous volumes.
The heterogeneous scattering code was arranged such that we can use a single
stratified random number for distance sampling, which gives less noise than
pseudo random numbers for each step. For volumes where the color is textured
there still seems to be something off, needs to be investigated.
This does not support staying fixed while the surface deforms, but for static
meshes it should match up with the surface texture coordinates. Implemented
as a matrix transform from objects space to mesh texture space.
Making this work for deforming surfaces would be quite complicated, you might
need something like harmonic coordinates as used in the mesh deform modifier,
probably will not be possible anytime soon.
Volumes can now have textured colors and density. There is a Volume Sampling
panel in the Render properties with these settings:
* Step size: distance between volume shader samples when rendering the volume.
Lower values give more accurate and detailed results but also increased render
time.
* Max steps: maximum number of steps through the volume before giving up, to
protect from extremely long render times with big objects or small step sizes.
This is much more compute intensive than homogeneous volume, so when you are not
using a texture you should enable the Homogeneous Volume option in the material
or world for faster rendering.
One important missing feature is that Generated texture coordinates are not yet
working in volumes, and they are the default coordinates for nearly all texture
nodes. So until that works you need to plug in object texture coordinates or a
world space position.
This is work by "storm", Stuart Broadfoot, Thomas Dinges and myself.
This is the simplest possible volume rendering case, constant density inside
the volume and no scattering or emission. My plan is to tweak, verify and commit
more volume rendering effects one by one, doing it all at once makes it
difficult to verify correctness and track down bugs.
Documentation is here:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Materials/Volume
Currently this hooks into path tracing in 3 ways, which should get us pretty
far until we add more advanced light sampling. These 3 hooks are repeated in
the path tracing, branched path tracing and transparent shadow code:
* Determine active volume shader at start of the path
* Change active volume shader on transmission through a surface
* Light attenuation over line segments between camera, surfaces and background
This is work by "storm", Stuart Broadfoot, Thomas Dinges and myself.
