The was actually caused by the way how Cycles uses objects
layers. It's not possible to rely on the fact that layers
are flushed from Base to Object. It's only valid when rendering
active scene.
Now made it so layers are used from the base.
Notes:
* The motion steps only affect deformation motion blur.
* The actual number of steps is 2^(steps - 1). This avoids having to sample at
many different times for object with more/fewer steps, now the times overlap.
* Deformation motion blur is enabled by default in existing files that have
motion blur enabled. If the object is not deforming, this will be detected at
export time, so raytracing performance will not be affected.
Part of the code is from the summer of code project by Gavin Howard.
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.
There are a couple of bugs that come together here:
* Particle hacks: extra modifier stack evaluation just for particles in
rna_Object_create_duplilist. This is where the primary issue stems from,
the "for_render" setting replaced the G.is_rendering flag in threaded
depsgraph. This causes particles to recalculate the entire modifier
stack with _render_ settings instead of viewport settings now. Fixed by
taking the 'preview' parameter in Cycles into account.
* Buggy skin modifier: The skin modifier generates a different amount of
vertices and faces **on every execution**. This must be looked at
separately, but it could be another reason why cycles constantly
restarted the sync process.
* Particles get re-distributed randomly every time (changing seed). This
could be caused just by the broken skin modifier, but might still be an
issue when simply rendering with cycles, since the psys will be
evaluated for render settings, if just temporarily.
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
* Add a "Total Samples" info at the bottom of the panel.
This makes understanding the Non-Progressive integrator easier, as it displays how many samples are used for the different ray types.
* Rename Squared Samples to Square samples, to indicate that the action is not already done. The new Total Samples info should make this easier to understand now as well. Also added back for Progressive integrator, for consistency.
Screenshot:
http://www.pasteall.org/pic/show.php?id=57980
New features:
* Bump mapping now works with SSS
* Texture Blur factor for SSS, see the documentation for details:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Shaders#Subsurface_Scattering
Work in progress for feedback:
Initial implementation of the "BSSRDF Importance Sampling" paper, which uses
a different importance sampling method. It gives better quality results in
many ways, with the availability of both Cubic and Gaussian falloff functions,
but also tends to be more noisy when using the progressive integrator and does
not give great results with some geometry. It works quite well for the
non-progressive integrator and is often less noisy there.
This code may still change a lot, so unless you're testing it may be best to
stick to the Compatible falloff function.
Skin test render and file that takes advantage of the gaussian falloff:
http://www.pasteall.org/pic/show.php?id=57661http://www.pasteall.org/pic/show.php?id=57662http://www.pasteall.org/blend/23501
* Add a "Squared Samples" option to the UI, to use squared values for ease of use. This can make it easier from an artist point of view, to weak settings.
With this enabled, all Sample values will be squared. So 10 Samples become 100 Samples.
For the Non-Progressive integrator: 4 AA Samples * 5 Diffuse Samples would become 16 AA Samples * 25 Diffuse = 400 in total.
Patch by Matt Heimlich, with some minor edits by myself. Thanks!
multiple importance sampling, so you can disable them for diffuse/glossy/transmission.
The Light Path node here is still weak and does not give this info. To make that
work we'd need to evaluate the shader multiple times which is slow and we can't
detect well enough when it is actually needed.
big lamps and sharp glossy reflections. This was already supported for mesh
lights and the background, so lamps should do it too.
This is not for free and it's a bit slower than I hoped even though there is
no extra BVH ray intersection. I'll try to optimize it more later.
* Area lights look a bit different now, they had the wrong shape before.
* Also fixes a sampling issue in the non-progressive integrator.
* Only enabled for the CPU, will test on the GPU later.
* An option to disable this will be added for situations where it does not help.
Same time comparison before/after:
http://www.pasteall.org/pic/show.php?id=43313http://www.pasteall.org/pic/show.php?id=43314
Patch [#33445] - Experimental Cycles Hair Rendering (CPU only)
This patch allows hair data to be exported to cycles and introduces a new line segment primitive to render with.
The UI appears under the particle tab and there is a new hair info node available.
It is only available under the experimental feature set and for cpu rendering.
There were a bunch of other issues with dupli motion blur and syncing, the problem
being that there was no proper way to detect corresponding duplis between frames
or updates. As a solution, a persistent_id was added to the DupliObject. It's an
extension of the previous index value, with one index for each dupli level. This
can be used to reliably find matching dupli objects between frames. Works with
nested duplis, multiple particle systems, etc.
The emitter visibility option is messy design, it makes such checks unnecessarily complicated. A better approach would be to allow non-mesh objects to carry particle data, these objects would just be invisible anyway without having to care about extra settings. However, this conflicts with the simplistic particle design of "owner is the emitter" ...
Generated and UV coordinates from the duplicator of instance instead of the
object itself.
This was used in e.g. Big Buck Bunny for texturing instanced feathers with
a UV map on the bird. Many files changed, mainly to do some refactoring to
get rid of G.rendering global in duplilist code.
Regular rendering now works tiled, and supports save buffers to save memory
during render and cache render results.
Brick texture node by Thomas.
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Textures#Brick_Texture
Image texture Blended Box Mapping.
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Textures#Image_Texturehttp://mango.blender.org/production/blended_box/
Various bug fixes by Sergey and Campbell.
* Fix for reading freed memory in some node setups.
* Fix incorrect memory read when synchronizing mesh motion.
* Fix crash appearing when direct light usage is different on different layers.
* Fix for vector pass gives wrong result in some circumstances.
* Fix for wrong resolution used for rendering Render Layer node.
* Option to cancel rendering when doing initial synchronization.
* No more texture limit when using CPU render.
* Many fixes for new tiled rendering.
The particle data used by the Particle Info node was stored in cycles as a list in each object. This is a problem when the particle emitter mesh is hidden: Objects in cycles are only intended as instances of renderable meshes, so when hiding the emitter mesh the particle data doesn't get stored either. Also the particle data can potentially be copied to multiple instances of the same object, which is a waste of texture space.
The solution in this patch is to make a completely separate list of particle systems in the Cycles scene data. This way the particle data can be generated even when the emitter object itself is not visible.
