Most of the changes are related to adding support for motion data throughout
the code. There's some code for actual camera/object motion blur raytracing
but it's unfinished (it badly slows down the raytracing kernel even when the
option is turned off), so that code it disabled still.
Motion vector export from Blender tries to avoid computing derived meshes
when the mesh does not have a deforming modifier, and it also won't store
motion vectors for every vertex if only the object or camera is moving.
=== BVH build time optimizations ===
* BVH building was multithreaded. Not all building is multithreaded, packing
and the initial bounding/splitting is still single threaded, but recursive
splitting is, which was the main bottleneck.
* Object splitting now uses binning rather than sorting of all elements, using
code from the Embree raytracer from Intel.
http://software.intel.com/en-us/articles/embree-photo-realistic-ray-tracing-kernels/
* Other small changes to avoid allocations, pack memory more tightly, avoid
some unnecessary operations, ...
These optimizations do not work yet when Spatial Splits are enabled, for that
more work is needed. There's also other optimizations still needed, in
particular for the case of many low poly objects, the packing step and node
memory allocation.
BVH raytracing time should remain about the same, but BVH build time should be
significantly reduced, test here show speedup of about 5x to 10x on a dual core
and 5x to 25x on an 8-core machine, depending on the scene.
=== Threads ===
Centralized task scheduler for multithreading, which is basically the
CPU device threading code wrapped into something reusable.
Basic idea is that there is a single TaskScheduler that keeps a pool of threads,
one for each core. Other places in the code can then create a TaskPool that they
can drop Tasks in to be executed by the scheduler, and wait for them to complete
or cancel them early.
=== Normal ====
Added a Normal output to the texture coordinate node. This currently
gives the object space normal, which is the same under object animation.
In the future this might become a "generated" normal so it's also stable for
deforming objects, but for now it's already useful for non-deforming objects.
=== Render Layers ===
Per render layer Samples control, leaving it to 0 will use the common scene
setting.
Environment pass will now render environment even if film is set to transparent.
Exclude Layers" added. Scene layers (all object that influence the render,
directly or indirectly) are shared between all render layers. However sometimes
it's useful to leave out some object influence for a particular render layer.
That's what this option allows you to do.
=== Filter Glossy ===
When using a value higher than 0.0, this will blur glossy reflections after
blurry bounces, to reduce noise at the cost of accuracy. 1.0 is a good
starting value to tweak.
Some light paths have a low probability of being found while contributing much
light to the pixel. As a result these light paths will be found in some pixels
and not in others, causing fireflies. An example of such a difficult path might
be a small light that is causing a small specular highlight on a sharp glossy
material, which we are seeing through a rough glossy material. With path tracing
it is difficult to find the specular highlight, but if we increase the roughness
on the material the highlight gets bigger and softer, and so easier to find.
Often this blurring will be hardly noticeable, because we are seeing it through
a blurry material anyway, but there are also cases where this will lead to a
loss of detail in lighting.
but this makes it more reliable for now.
Also add an integrator "Clamp" option, to clamp very light samples to a maximum
value. This will reduce accuracy but may help reducing noise and speed up
convergence.
emitting objects or world lighting do not contribute to the shadow pass.
Consider this more as a pass useful for some compositing tricks, unlike
other lighting passes this pass can't be used to exactly reconstruct the
combined pass.
existing "Equirectangular". This projection is useful to create light probes
from a chrome ball placed in a real scene. It expects as input a photograph of
the chrome ball, cropped so the ball just fits inside the image boundaries.
Example setup with panorama camera and mixing two (poor quality) photographs
from different viewpoints to avoid stretching and hide the photographer:
http://www.pasteall.org/pic/28036
and 5 float image textures. For CPU render this limit will be lifted later
on with image cache support. Patch by Mike Farnsworth.
Also changed color space option in image/environment texture node, to show
options Color and Non-Color Data, instead of sRGB and Linear, this is more
descriptive, and it was not really correct to equate Non-Color Data with
Linear.
environment map, by enabling the Panorama option in the camera.
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Camera#Panorama
The focal length or sensor settings are not used, the UI can be tweaked still to
communicate this, also panorama should probably become a proper camera type like
perspective or ortho.
Currently supported passes:
* Combined, Z, Normal, Object Index, Material Index, Emission, Environment,
Diffuse/Glossy/Transmission x Direct/Indirect/Color
Not supported yet:
* UV, Vector, Mist
Only enabled for CPU devices at the moment, will do GPU tweaks tommorrow,
also for environment importance sampling.
Documentation:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Passes
Contrast helps to adjust IBL (HDR images used for background lighting).
Note: In the UI we are caling it Bright instead of Brightness. This copy what Blender composite is doing.
Note2: the algorithm we are using produces pure black when contrast is 100. I'm not a fan of that, but it's a division by zero. I would like to look at other algorithms (what gimp does for example). But that would be only after 2.62.
By default lighting from the world is computed solely with indirect light
sampling. However for more complex environment maps this can be too noisy, as
sampling the BSDF may not easily find the highlights in the environment map
image. By enabling this option, the world background will be sampled as a lamp,
with lighter parts automatically given more samples.
Map Resolution specifies the size of the importance map (res x res). Before
rendering starts, an importance map is generated by "baking" a grayscale image
from the world shader. This will then be used to determine which parts of the
background are light and so should receive more samples than darker parts.
Higher resolutions will result in more accurate sampling but take more setup
time and memory.
Patch by Mike Farnsworth, thanks!
disk to be reused by the next render.
This is useful for rendering animations where only the camera or materials change.
Note that saving the BVH to disk only to be removed for the next frame is slower
if this is not the case and the meshes do actually change.
For a render, it will save bvh files to the cache user directory, and remove all
cache files from other renders. The files are named using a MD5 hash based on the
mesh, to verify if the meshes are still the same.
The rendering device is now set in User Preferences > System, where you can
choose between OpenCL/CUDA and devices. Per scene you can then still choose
to use CPU or GPU rendering.
Load balancing still needs to be improved, now it just splits the entire
render in two, that will be done in a separate commit.
This allows group nodes inside other group nodes in cycles and makes the
code more generic for all possible cases, like direct group
input-to-output links and unused group sockets.
Previous code tried to connect external nodes and internal group sockets
by following links until a "real" node input/output. This quickly
becomes complicated in corner cases as described above and can lead to
unexpected behavior when the group socket is of a different type than
the internal/external sockets, but that conversion is skipped.
The new code uses the concept of "proxy nodes" similar to what the new
compositor does. Each group socket is replaced with a proxy node with a
single input and output, to which other nodes in the same tree and
internal nodes can link to. After all groups have been expanded in the
graph, these proxy nodes are removed again, adding converter nodes if
necessary.
Node specially useful for Texture correction.
This is also a nice example of a simple node made from scratch in case someone wants to create their custom nodes.
Review by Brecht.
reviewed by Brecht, with help from Lukas.
Note: dot is reversed compared to Blender.
In Blender Normals point outside, while in Cycles they point inside.
If you use your own custom vector with the Normal Node you will see a difference.
If you feed it with object normals it should work just as good.
lower than 1.3, since we're not officially supporting these. We're already not
providing CUDA binaries for these, so better make it clear when compiling from
source too.
as with the HSV node the OSL code is relying on the (yet to be implemented) autorename.
Also the svm code could use mix (svm_lerp) instead:
32 . float3 color_inv = make_float3(1.0f, 1.0f, 1.0f) - color;
35 . . stack_store_float3(stack, out_color, svm_lerp(color_inv, color, factor));
I have a feeling that each node 'program' should have the least program as possible. I'll see with Brecht later.
But overall I don't know if that's any fast. And apart from that I think we will need this kind of function to move to a library if multiple functions linked in are not a problem.
----------------------------
reviewed and approved by Brecht
Important note:
the camera Z is reverted compared to Blender render.
Now it goes from zero (camera) to positive (in front of the camera)
