Problem: artist wants character to walk in grass, but still have all rendered
in seperate render-layers, for postpro effects and vblur. How to efficiently
create a mask image you can put *over* the character for the grass?
Solution has two parts; this commits allows any layer inside of the renderlayers
to become a Z-mask (Z values for solid gets filled in, but not rendered).
Second part of commit is render option "Only render stuff that's in front of
a zbuffer value that was filled in (saves render time)
of strands changing between frames, vector blur couldn't work. Now
speed vectors are interpolated from the surface. This also means
child particles don't have to be computed in the previous and next
frames, so saves time too.
Also, duplis are now taking into account, the proper way to exclude
them is to set the material to be not traceable.
Removed an unnecessary pointer from the VlakRen struct to save some
memory, not really that significant, but still, saves 70 mb for 10
million faces.
Especially for fast moving objects (as we have here in Peach) the
art department demanded nice curved vector blur. This formula uses
a quadratic bezier function, which is not giving perfect circles, but
certainly useful results.
Also on todo: get this blur code to do nicer accumulation...
- Particle system distribution wasn't flushed properly for non-edited hair.
- For instances in the renderer, also count their verts and faces in the stats.
- Fix for error in the "surface diffuse" formula for strand shading.
Removed FTYPE from render output panel - was some old format that did index colors, and wasn't even used anywhere.
Added 2 options to the render output panel that can be used for a really basic local renderfarm (even artists can use it!),
"NoOverwrite" and "Touch"
When both are enabled, rendering 1 scene between many pc's on a fast network will populate the directory with frames.
Also useful to delete frames that have errors and re-render (without manually re-rendering each frame)
- non OSA case didn't work
- ztransp adding was accidentally using an incorrect alpha value
NOTE: allmost all pass types rendered in OSA with a filter (not box!) were
incorrectly added on solid layers. Like diffuse, AO, etc.
This is actually just the alpha value as currently being calculated
by the mist code. It is in many cases not very useful to have this as
alpha in shading result, also for postprocess and composite.
Note: this pass also works with "Mist" not set in World, of course.
=============================
A new approximate ambient occlusion method has been added, next to the
existing one based on raytracing. This method is specifically targetted
at use in animations, since it is inherently noise free, and so will
not flicker across frames.
http://www.blender.org/development/current-projects/changes-since-244/approximate-ambient-occlusion/http://peach.blender.org/index.php/approximate-ambient-occlusion/
Further improvements are still needed, but it can be tested already. There
are still a number of known issues:
- Bias errors on backfaces.
- For performance, instanced object do not occlude currently.
- Sky textures don't work well, the derivatives for texture evaluation
are not correct.
- Multiple passes do not work entirely correct (they are not accurate
to begin with, but could be better).
Lampbuffers require painful bias tweaking (to prevent aliasing or to
get shadow detail). Sometimes you want this different per object, like
for gras you want less shadow detail, but for the ground you want high
detail. This feature allows to tweak it.
The new "LBias" slider is in shader panel, bottom. Ugly! But, thats for
later...
It seems everytime I try to fix something here I break something
else, but anyway, another try at getting this to work properly.
Fixes for:
- Getting dupliverts/faces derivedmesh with orco caused wrong results
on meshes in linked dupligroups with proxy, because modifier stack
was revaluated with wrong object matrix, now gets orco another way.
- Fix render instances being hidden when original object was not added
to the object render list.
- Changed the way object instances find their original objects, now
works the other way around, original objects look for their instances
instead.
There's probably issues still with recursive dupligroups..
[#6861] Black dots when using small lamps on Mirror materials in 2.44 and 2.43.
some values were not initialized properly, for example, the window coordinates for reflections, this caused NAN color values for some pixels, (may also fix plumiferos bad pixel problem from last bconf)
====================
- "From Dupli" option for orco and uv texture coordinates. For dupliverts,
duplifaces and dupli particles, this uses the orco and uv at the point
on the parent surface. Can for example be used for texturing feathers
and leafs. Note that uv only works for duplifaces and particles emitted
from faces, these are not defined at vertices.
- "Width Fade" option for strand render, to fade out along the width of the
strand. Committing this so it can be tested, might be changed or removed
even, if it doesn't give nice results.
* Most were uninitialised vars
* Fixed whitespace in a few places
* The change I made in rendercore.c -> do_bake_shade() was for an uninitialised var, but I hope it does't cause any rendering errors...
at all if you use new 'minimal' option. The new option works much nicer
if it only sets the minimum. (use texture with 'refl' map)
Added option to env map too!
Image texture "Filter size" was not well usable for making the
appearance soft filtered, this because it multiplied the sample
values, and such values could be extreme small.
Added next to "Filter" buton a new "Min" option, which enforces
a filter size to be a minimum of 'filter' pixels in size.
============================
- Strand render now has options to remove child strands as
the object's faces becomes smaller, in the Simplification
particle panel.
- "Reference Size" is the approximate size of the object on
screen, after which simplification starts.
- "Rate" is how fast strands are removed.
- "Transition" is the percentage of strands being faded out as
they are removed.
- Another "Viewport" option removes strands on faces that are
outside of the viewport. "Rate" again controls how fast these
are removed.
- Strand render in Blender Units now has an adjustable minimum
width. Below this minimum width, strands start fading out
instead of getting smaller.
=========
- The render and realtime button for the particle system modifier
and the enabled button for particles now work seperate again,
made a bad design decision to tie them together. Now with only
the render button and not realtime enabled it renders.
- Fix for bug #7948: particle mode crash while constraining axis.
- Fix for bug #7945: crash loading effector groups from an old file.
- Fix for bug #7942: crash for reactor particles emitting from particles.
===============================
- One shadowbuffer per thread.
- Added more break tests in shadow buffer code.
- Removed R.clipcrop global, solution is not nice yet, but at
least threadsafe.
- Fixed bug in strand render shadow buffer code.
=================
Big commit, but little user visible changes.
- Dupliverts and duplifaces are now rendered as instances, instead
of storing all of the geometry for each dupli, now an instance is
created with a matrix transform refering to the source object.
This should allow us to render tree leaves more memory efficient.
- Radiosity and to some degree raytracing of such objects is not
really efficient still. For radiosity this is fundamentally hard
to solve, but raytracing an octree could be created for each object,
but the current octree code with it's fixed size doesn't allow this
efficiently.
- The regression tests survived, but with I expect that some bugs will
pop up .. hopefully not too many :).
Implementation Notes
====================
- Dupligroups and linked meshes are not rendered as instances yet,
since they can in fact be different due to various reasons,
instancing of these types of duplis that are the same can be added
for them at a later point.
- Each ObjectRen now stores it's own database, instead of there being
one big databases of faces, verts, .. . Which objects that are actually
rendered are defined by the list of ObjectRenInstances, which all refer
to an ObjectRen.
- Homogeneous coordinatess and clipping is now not stored in vertices
anymore, but instead computed on the fly. This couldn't work for
instances. That does mean some extra computation has to be done, but
memory lookups can be slow too, and this saves some memory. Overall
I didn't find a significant speed impact.
- OSA rendering for solid and ztransp now is different. Instead of e.g.
going 8 times over the databases times and rendering the z-buffer, it
now goes over the database once and renders each polygon 8 times. That
was necessary to keep instances efficient, and can also give some
performance improvement without instances.
- There was already instancing support in the yafray export code, now it
uses Blender's render instances for export.
- UV and color layer storage in the render was a bit messy before, now
should be easier to understand.
- convertblender.c was reorganized somewhat. Regular render, speedvector
and baking now use a single function to create the database, previously
there was code duplicated for it.
- Some of these changes were done with future multithreading of scene
and shadow buffer creation in mind, though especially for scene creation
much work remains to be done to make it threadsafe, since it also involves
a lot of code from blenkernel, and there is an ugly conflict with the way
dupli groups work here .. though in the render code itself it's almost there.
