This commit introduces a new texture ('Voxel Data'), used to load up saved voxel
data sets for rendering, contributed by Raúl 'farsthary' Fernández Hernández
with some additional tweaks. Thanks, Raúl!
The texture works similar to the existing point density texture, currently it
only provides intensity information, which can then be mapped (for example) to
density in a volume material. This is an early version, intended to read the
voxel format saved by Raúl's command line simulators, in future revisions
there's potential for making a more full-featured 'Blender voxel file format',
and also for supporting other formats too.
Note: Due to some subtleties in Raúl's existing released simulators, in order
to load them correctly the voxel data texture, you'll need to raise the
'resolution' value by 2. So if you baked out the simulation at resolution 50,
enter 52 for the resolution in the texture panel. This can possibly be fixed in
the simulator later on.
Right now, the way the texture is mapped is just in the space 0,0,0 <-> 1,1,1
and it can appear rotated 90 degrees incorrectly. This will be tackled, for now,
probably the easiest way to map it is with and empty, using Map Input -> Object.
Smoke test: http://www.vimeo.com/2449270
One more note, trilinear interpolation seems a bit slow at the moment, we'll
look into this.
For curiosity, while testing/debugging this, I made a script that exports a mesh
to voxel data. Here's a test of grogan (www.kajimba.com) converted to voxels,
rendered as a volume: http://www.vimeo.com/2512028
The script is available here: http://mke3.net/projects/bpython/export_object_voxeldata.py
* Another smaller thing, brought back early ray termination (was disabled
previously for debugging) and made it user configurable. It now appears as a new
value in the volume material: 'Depth Cutoff'. For some background info on what
this does, check:
http://farsthary.wordpress.com/2008/12/11/cutting-down-render-times/
* Also some disabled work-in-progess code for light cache
Robin (Frrr) Allen did a decent job on this, so we can also welcome him
as a member in the svn committers team to maintain it!
I do the first commit with some minor fixes:
- get Makefiles work
- fix rounding issue with tiles on unit faces
- removed UI includes from tex node
A nice doc in wiki is here:
http://wiki.blender.org/index.php/User:Frr/TexnodeManual
On the todo for Robin is:
- When using one or more Texture-input nodes, you cannot edit them by activating
(as works now for Material nodes).
- The new "output node" option fails on the default case, when only one
output node is active. It then shows often a blank menu. Will get fixed asap.
- When using a NodeTree-Texture as input node, the menu for 'active output'
should not show. NodeTree should ignore other nodetrees to keep things sane
for now.
- On a future todo is proper usage of "Dxt" and "Dyt" texture vectors for
superior antialising of checkers/bricks.
General note; I know people are dying to get a full integrated shader system
with nodes. In theory we could merge this with Material Nodetrees... but I
rather wait for a solid and very well thought out design proposal for this,
also including design ideas for unifying with a shader language (GPU, CPU).
For the time being this is a nice extension of current textures. :)
* Fixed a stupid crash caused by last commit that worked fine on the mac
(but never should have...)
* Fix for using child particles with the new particle age color options
This introduces a few new ways of modifying the intensity and colour output
generated by the Point Density texture. Previously, the texture only output
intensity information, but now you can map it to colours along a gradient
ramp, based on information coming out of a particle system.
This lets you do things like colour a particle system based on the individual
particles' age - the main reason I need it is to fade particles out over time.
The colorband influences both the colour and intensity (using the colorband's
alpha value), which makes it easy to map a single point density texture to
both intensity values in the Map To panel (such as density or emit) and colour
values (such as absorb col or emit col). This is how the below examples are
set up, an example .blend file is available here:
http://mke3.net/blender/devel/rendering/volumetrics/pd_test4.blend
The different modes:
* Constant
No modifications to intensity or colour (pure white)
* Particle Age
Maps the color ramp along the particles' lifetimes:
http://mke3.net/blender/devel/rendering/volumetrics/pd_mod_partage.mov
* Particle Speed
Maps the color ramp to the particles' absolute speed per frame (in Blender
units). There's an additional scale parameter that you can use to bring this
speed into a 0.0 - 1.0 range, if your particles are travelling too faster or
slower than 0-1.
http://mke3.net/blender/devel/rendering/volumetrics/pd_mod_speed.mov
* Velocity -> RGB
Outputs the particle XYZ velocity vector as RGB colours. This may be useful
for comp work, or maybe in the future things like displacement. Again, there's
a scale parameter to control it.
http://mke3.net/blender/devel/rendering/volumetrics/pd_mod_velrgb.mov
* When making a proxy, the lib linked IPO driver was also changed to
point to the proxy object, and after undo this local proxy object
was replaced so the pointer became invalid. In fact it is not needed
at all to change this because the IPO code maps the pointer to the
local proxy object already.
* Undoing the make proxy operation would crash because the proxy_from
pointer in the library linked object would still point to the removed
object. Now it clears all these pointers before undo, because on each
undo memory file read they will be set again anyway.
before, but wasn't playing nice with the other force fields (was
overwriting the velocity rather than acting as a force). This version is
slightly different, but will work a lot better with other force fields too.
It works similarly to Vortex, but it's a more controllable - it
doesn't send the particles off accelerating into space, but
keeps them spinning around the Z axis of the force field object.
This is safe in the branch, but Jahka if you have any feedback,
I'd be curious to hear :)
Replaced 'Sharp' falloff with 'Soft'. This falloff type has
a variable softness, and can get some quite smooth results.
It can be useful to get smooth transitions in density when
you're using particles on a large scale:
http://mke3.net/blender/devel/rendering/volumetrics/pd_falloff_soft.jpg
Also removed 'angular velocity' turbulence source - it
wasn't doing anything useful atm
This was a bit complicated to do, but is working pretty well now, and can make shading significantly faster to render.
This option pre-calculates self-shading information into a
3d voxel grid before rendering, then uses and interpolates
that data during the main rendering phase, rather than
calculating shading for each sample. It's an approximation
and isn't as accurate as getting the lighting directly,
but in many cases it looks very similar and renders much faster.
The voxel grid covers the object's 3D screen-aligned bounding box
so this may not be that useful for large volume regions like a
big range of cloud cover, since you'll need a lot of resolution.
The render time speaks for itself here:
http://mke3.net/blender/devel/rendering/volumetrics/vol_light_cache_interpolation.jpg
The resolution is set in the volume panel - it's the resolution
of one edge of the voxel grid. Keep in mind that the higher the
resolution, the more memory needed, like in fluid sim. The
memory requirements increase with the cube of the edge
resolution so be careful. I might try and add a little memory
calculator thing like fluid sim has there later.
The voxels are interpolated using trilinear interpolation -
here's a comparison image I made during testing:
http://mke3.net/blender/devel/rendering/volumetrics/vol_light_cache_compare.jpg
There might still be a couple of little tweaks I can do to
improve the visual quality, I'll see.
- modified point density so that it returns a more consistent
density with regards to search radius. Previously larger radii
would give much higher density but this is equalised out now.
- Added a new volume material option 'density scale'. This is an
overall scale multiplier for density, allowing you to (for
example) crank down the density to a more desirable range if
you're working at a large physical scale. Volume rendering is
fundamentally scale dependant so this lets you correct to get the
right visual result.
- Also tweaked a few constants, old files won't render exactly
the same, just minor things though.
Enable soft body collision clusters by default.
Add option to 'disable collision' button between soft body and rigid body connected by constraint (option was already available between two rigid bodies)
Definitely one of the oldest bugs ever (1995 or so).
Case is a path (child on path, or deformer, or motion modifier) where the
child is far away from path (300 units or so). In that case you can see
the path jumping to another position a bit after a few frames.
Reason:
For interpolating path positions, I was using bspline code still having a
very ancient constant 0.1666f.
Floats have higher precision, like 0.16666666. That solved it :)
Playanim now works for:
- tiff, cineon, dpx, hdr, exr
Only multilayer not, that's too much for a bugfix. Multilayer is a totally
different image format, handled separately.
ALso removed redundant printing for dpx/cineon.
And fixed crash in cineon when G.scene doesnt exist. Bad bad, should
not be there!
