This is done using the existing Emission node and closure (we may add a volume
emission node, not clear yet if it will be needed).
Volume emission only supports indirect light sampling which means it's not very
efficient to make small or far away bright light sources. Using direct light
sampling and MIS would be tricky and probably won't be added anytime soon. Other
renderers don't support this either as far as I know, lamps and ray visibility
tricks may be used instead.
This works pretty much as you would expect, overlapping volume objects gives
a more dense volume. What did change is that world volume shaders are now
active everywhere, they are no longer excluded inside objects.
This may not be desirable and we need to think of better control over this.
In some cases you clearly want it to happen, for example if you are rendering
a fire in a foggy environment. In other cases like the inside of a house you
may not want any fog, but it doesn't seem possible in general for the renderer
to automatically determine what is inside or outside of the house.
This is implemented using a simple fixed size array of shader/object ID pairs,
limited to max 15 overlapping objects. The closures from all shaders are put
into a single closure array, exactly the same as if an add shader was used to
combine them.
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.
* Henyey-Greenstein scattering closure implementation.
* Rename transparent to absorption node and isotropic to scatter node.
* Volume density is folded into the closure weights.
* OSL support for volume closures and nodes.
* This commit has no user visible changes, there is no volume render code yet.
This is work by "storm", Stuart Broadfoot, Thomas Dinges and myself.
* UI: Remove deprecated condition (CURVE_RIBBONS) and hide backface property, when it's hardcoded in C (Curve/Line segments && Ribbons).
* Remove "use_tangent_normal" and "CURVE_KN_TANGENTGNORMAL" as its unused (follow up for last commit).
* Remove dead code from line segments BVH refine.
CURVE_KN_TANGENTGNORMAL and CURVE_KN_TRUETANGENTGNORMAL are either both true, or both false. Therefore a true/false condition is impossible.
This was a leftover of CURVE_CUSTOM, which was removed in r59234.
* Use "else if" in blender_curves.cpp.
Issue was caused by recent image cache rewrite and root of
the issue goes to the fact that blender player doesn't
initialize cache limiter and it uses 32meg of memory only.
This leads to infinite image loading/freeing.
For now disabled cache limiter in game engine, this brings
back old behavior.
In theory we might be smarter here, but better caching
policy is to be discussed.
This callback is used when cache limiter needs to remove
some cached objects when running out of limit.
From blender side it's used to keep painted images always
in memory.
This fixes issue when painted images were removing from
the memory after image cache rewrite.
Summary:
Mainly addressed to solve old TODO with color managed fallback
to CPU mode when displaying render result during rendering.
That fallback was caused by the fact that partial image update
was always acquiring image buffer for composite output and was
only modifying display buffer directly.
This was a big issue for Cycles rendering which renders layers
one by one and wanted to display progress of each individual
layer. This lead to situations when display buffer was based on
what Cycles passes via RenderResult and didn't take layer/pass
from image editor header into account.
Now made it so image buffer which partial update is operating
with always corresponds to what is set in image editor header.
To make Cycles displaying progress of all the layers one by one
made it so image_rect_update switches image editor user to
newly rendering render layer. It happens only once when render
engine starts rendering next render layer, so should not be
annoying for navigation during rendering.
Additional change to render engines was done to make it so
they're able to merge composite output to final result
without marking tile as done. This is done via do_merge_result
argument to end_result() callback. This argument is optional
so should not break script compatibility.
Additional changes:
- Partial display update for Blender Internal now happens from
the same thread as tile rendering. This makes it so display
conversion (which could be pretty heavy actually) is done in
separate threads. Also gives better UI feedback when rendering
easy scene with small tiles.
- Avoid freeing/allocating byte buffer for render result
if it's owned by the image buffer. Only mark it as invalid
for color management.
Saves loads of buffer re-allocations in cases when having
several image editors opened with render result. This change
in conjunction with the rest of the patch gave around
50%-100% speedup of render time when displaying non-combined
pass during rendering on my laptop.
- Partial display buffer update was wrong for buffers with number
of channels different from 4.
- Remove unused window from RenderJob.
- Made image_buffer_rect_update static since it's only used
in single file.
Reviewers: brecht
Reviewed By: brecht
CC: dingto
Differential Revision: http://developer.blender.org/D98
After update to Mac OS X 10.9.1, OpenCL works now on my Intel CPU in the 2013 Macbook Pro (even the entire kernel).
The Intel Iris Pro GPU still segfaults here though, even when all flags are disabled (building "clay like" kernel only).
Maybe we need the -no-missing-prototypes for AMD hardware still, but I couldn't find a way to distuinguish here.
The GLSL function textureSize() is not supported here, only when we start using
OpenGL core profile will this work. For now check the supported GLSL version and
use a somewhat slower replacement.
Summary:
Uses some magic pseudo-random which is actually a
texture coordinate hashing function.
TODOs:
- Dither noise is the same for all the frames.
- It's different from Floyd's dither we've been
using before.
- Currently CPU and GPU dithering used different
implementation. Ideally we need to use the same
dither in CPU.
Reviewers: brecht
Reviewed By: brecht
Differential Revision: http://developer.blender.org/D58
Summary:
Version of those libraries might be useful to know.
- OIIO and OCIO is exposed via bpy.app.oiio and bpy.app.ocio.
There're "supported", "version" and "version_string" defined
in those modules.
- OSL is available as _cycles.osl_version and _cycles.osl_version_string.
Reviewers: campbellbarton
Reviewed By: campbellbarton
CC: dingto
Differential Revision: http://developer.blender.org/D79
