Volumes can now receive shadows from external objects, either raytraced shadows or shadow maps.
To use external shadows, enable 'external shadows' in volume material 'lighting' panel. This an extra toggle since it causes a performance hit, but this can probably be revisited/optimised when the new raytrace accelerator is integrated. For shadow maps at least, it's still very quick.
Renamed 'scattering mode' to 'lighting mode' (a bit simpler to understand), and the options inside. Now there's:
- Shadeless
takes light contribution, but without shadowing or self-shading (fast)
good for fog-like volumes, such as mist, or underwater effects
- Shadowed (new)
takes light contribution with shadows, but no self-shading. (medium)
good for mist etc. with directional light sources
eg. http://vimeo.com/6901636
- Shaded
takes light contribution with internal/external shadows, and self shading (slower)
good for thicker/textured volumes like smoke
- Multiple scattering etc (still doesn't work properly, on the todo).
* Rendering twice or more could crash layer/pass buttons.
* Compositing would crash while drawing the image.
* Rendering animations could also crash drawing the image.
* Compositing could crash
* Starting to rendering while preview render / compo was
still running could crash.
* Exiting while rendering an animation would not abort the
renderer properly, making Blender seemingly freeze.
* Fixes theoretically possible issue with setting malloc
lock with nested threads.
* Drawing previews inside nodes could crash when those nodes
were being rendered at the same time.
There's more crashes, manipulating the scene data or undo can
still crash, this commit only focuses on making sure the image
buffer and render result access is thread safe.
Implementation:
* Rather than assuming the render result does not get freed
during render, which seems to be quite difficult to do given
that e.g. the compositor is allowed to change the size of
the buffer or output different passes, the render result is
now protected with a read/write mutex.
* The read/write mutex allows multiple readers (and pixel
writers) at the same time, but only allows one writer to
manipulate the data structure.
* Added BKE_image_acquire_ibuf/BKE_image_release_ibuf to access
images being rendered, cases where this is not needed (most
code) can still use BKE_image_get_ibuf.
* The job manager now allows only one rendering job at the same
time, rather than the G.rendering check which was not reliable.
After code review and experimentation, this commit makes some changes to the way that volumes are shaded. Previously, there were problems with the 'scattering' component, in that it wasn't physically correct - it didn't conserve energy and was just acting as a brightness multiplier. This has been changed to be more correct, so that as the light is scattered out of the volume, there is less remaining to penetrate through.
Since this behaviour is very similar to absorption but more useful, absorption has been removed and has been replaced by a 'transmission colour' - controlling the colour of light penetrating through the volume after it has been scattered/absorbed. As well as this, there's now 'reflection', a non-physically correct RGB multiplier for out-scattered light. This is handy for tweaking the overall colour of the volume, without having to worry about wavelength dependent absorption, and its effects on transmitted light. Now at least, even though there is the ability to tweak things non-physically, volume shading is physically based by default, and has a better combination of correctness and ease of use.
There's more detailed information and example images here:
http://wiki.blender.org/index.php/User:Broken/VolumeRendering
Also did some tweaks/optimisation:
* Removed shading step size (was a bit annoying, if it comes back, it will be in a different form)
* Removed phase function options, now just one asymmetry slider controls the range between back-scattering, isotropic scattering, and forward scattering. (note, more extreme values gives artifacts with light cache, will fix...)
* Disabled the extra 'bounce lights' from the preview render for volumes, speeds updates significantly
* Enabled voxeldata texture in preview render
* Fixed volume shadows (they were too dark, fixed by avoiding using the shadfac/AddAlphaLight stuff)
More revisions to come later...
Editors Modules
* render/ module added in editors, moved the preview render code there and
also shading related operators.
* physics/ module made more consistent with other modules. renaming files,
making a single physics_ops.c for operators and keymaps. Also move all
particle related operators here now.
* space_buttons/ now should have only operators relevant to the buttons
specificially.
Updates & Notifiers
* Material/Texture/World/Lamp can now be passed to DAG_id_flush_update,
which will go back to a callback in editors. Eventually these should
be in the depsgraph itself, but for now this gives a unified call for
doing updates.
* GLSL materials are now refreshed on changes. There's still various
cases missing,
* Preview icons now hook into this system, solving various update cases
that were missed before.
* Also fixes issue in my last commit, where some preview would not render,
problem is avoided in the new system.
Icon Rendering
* On systems with support for non-power of two textures, an OpenGL texture
is now used instead of glDrawPixels. This avoids problems with icons get
clipped on region borders. On my Linux desktop, this gives an 1.1x speedup,
and on my Mac laptop a 2.3x speedup overall in redrawing the full window,
with the default setup. The glDrawPixels implementation on Mac seems to
have a lot of overhread.
* Preview icons are now drawn using proper premul alpha, and never faded so
you can see them clearly.
* Also tried to fix issue with texture node preview rendering, globals can't
be used with threads reliably.
[#8358] Performance regression with raytraced refraction
Now shadows are only sampled once in reflections/refractions. For cases where this would be a problem (perfect specular reflection/refraction), the full OSA takes care of it.
* VecLerp3f and Vec2Lerp3f - interpolate 3 2d/3d vectors from 3 weights
* AngleToLength(angle) - useful for making even width shell/walls based on the angles of the surrounding geometry from each point. (same method used in 2.4x python solidify script).
also quiet some warnings.
New stuff
- Bending springs for hair dynamics.
Code cleanup & optimization
- Disabled reactor particles temporarily for cleanup, it's a clumsy system that will be replaced with something better.
- Removed child seams, something better will come here too :)
- Normal particle drawing data is now saved between redraws if the particles don't move between redraws.
* For example rotating the 3d view is now realtime even with 1M particles.
- Many random values for particles now come from a lookup table making things much faster.
- Most accessed small point cache functions are now much faster as macros.
- Lot's of general code cleanup.
- Nothing big should have changed so if something doesn't work like it used to it's probably just a typo somewhere :)
Note sure what to do with this one, and personally think
we should avoid using macros for this kind of thing:
V_GROW(edges);
source/blender/editors/mesh/loopcut.c:232: warning: value computed is not used
#19345: can't get out of grayed out pointer field.
#19342: item_pointerR fields can't be cleared with one item.
#19341: fix hanging tooltips when manipulating regions.
#19339: context panel still allowed tabbing, but it has no header.
#19334: editing SSS settings crashed previewrender.
#19330: object mode could not be switched on from the header menu.
#define RE_RAYCOUNTER (/source/blender/render/extern/include/RE_raytrace.h)
*Some other small organization on code
(will be disable as this only matters for testing and developping)
(this is a generalization of some of the experimental stuff i tried during SoC,
but only had time to improve a few days ago)
- it should yield slightly better results
- the cost model can somehow be tweaked to optimize for diferent trees.
*cleaned up some code
*added counters for number of SIMD BB tests
*added GPL license block on missing files
- Some big refresh issues with softbody & cloth point cache usage should now be fixed.
- Removed sticky objects from particles (better stuff will come back when I get to updating reactor particles).
- Some initial easy memory efficiency cleanup for ParticleData struct. The ultimate goal is to get particles less memory hungry -> more particles possible in single scene.
- Wrong path timing clamping caused hair particles to seem disappeared when changing between normal<->hair particles.
- "Calculate to current frame" in cache buttons baked instead of the intended function.
- Boids particle data is now a bit better organized.
Now there is (in order of speed):
* Nearest neighbour (very rough quality)
* Linear (medium quality)
* Quadratic (good quality)
* Cubic Catmull-rom (very good quality, crisp)
* Cubic B-spline (very good quality, smooth)
Thanks!
shr->spec values could be greater then 1.0, causing negative color when using (1.0-shr->spec[i]) as a blending factor.
When shr->spec[i] is 1.0 the mircol is ignored, so only mix the mircol when needed (like clamping the spec).
* Fix for plane material preview render. Now, light cache aborts if there isn't enough volume, and falls back on non-cached single scattering. It still doesn't make much sense to render a plane as a volume, but for now in the preview it will shade the region in between the plane and the checker background.
Also, made the Outliner's horizontal scrollbar work better for keymaps view. It's still using an approximation of the width, but at least you can scroll now.
Note that With libsndfile also need libflac and libogg here (Linux), right
now I just add this two librarys to the NAN_SNDFILELIBS, but maybe
it's better split this ? (NAN_FLAC/NAN_OGG)
Finally in 2.5 branch :)
Still things to do, but will continue working in here. I won't bother
repeating the commit messages from the last year or so, however I've
written up some technical docs to help Ton/Brecht/etc review and find
their way around the code:
http://wiki.blender.org/index.php/User:Broken/VolumeRenderingDev
That above page has some known issues and todos listed, but I'm still
interested in bug reports.
Credits for this code:
* Matt Ebb
(with thanks to Red Cartel/ProMotion Studios)
* Raul Fernandez Hernandez (Farsthary) for patches:
o Light cache based multiple scattering approximation
o Initial voxeldata texture code
o Depth Cutoff threshold
* Andre Susano Pinto for BVH range lookup addition
* Trilinear interpolation adapted from pbrt
* Tricubic interpolation from libtricubic
