A mesh can consist out of multiple material. Take a character with clothing's. the skin can be a different material as the different clothing's. During compositing it is a common use-case to only do a part of the composit on only a specific material. Currently this can not be done.
In blender movies this feature is known to be implemented, but until now it never got integrated into trunk.
Proposal
With material index the Blender internal renderer will be capable of creating a buffer containing the material indexes of the first pixel-hit. This will be implemented in the same manner as the object index.
In the compositor the ID Mask node can be used to extract the information out of the Render pass.
Impact
User interface
On the properties-space the next changes will be done
Scene⇒Render layer⇒Passes⇒Material index will be added
Material⇒Options⇒Pass index will be added
DNA
Material struct will get an new field called “index”. this will be a short-type.
Material struct the field pad will be removed.
A new Render-layer pass will be added (bit 1«18)
RNA
Material RNA is updated (based on “pass index” from object)
Render layer RNA is updated (based on IndexOB)
Blender internal renderer
The Blender internal renderer will process the render pass as a copy of the Object index.
Blender compositor
The render layer input will get a new output socket called “IndexMA”
Usage
An example on how to use material index can be found at:
https://svn.blender.org/svnroot/bf-blender/trunk/lib/tests/compositing/composite_materialindex.blend
This is also example of a commit message longer than the commit itself :)
In addition don't store unfinished links in the nodetree->links list any more. This makes code a bit safer because all links in that list can be considered valid now. The temporary bNodeLinkDrag structs used by the modal linking operator are now also stored in a list in SpaceNode, so these links can be drawn too (this separation also allows different display of temporary links, e.g. currently they are drawn on top of all nodes).
Node compositor crash:
When you very quickly unlink a socket *right* after connecting it
(within 0.1 second), the compositor started with a noodle without
valid connections, which was not foreseen to happen.
- "need exec" flag was cleared in wrong tree for preview renders
(it should clear it in the copy, i did in original).
This fixes projection paint on images with previews open
- Previews for nodes were copied always, now only for previews
invoked by node editor itself.
Two bugs in one:
- Lukas commit monday for new group/socket handling accidentally removed
to set socketype in stacks, which as used by (texture) nodes to detect
whether value, color or vector had to be read.
Result was that all texture nodes were rendering as B&W
- Old 2.5 bug: preview renders for texture nodes didn't call a
NodeEndExec function, which gave crashes on deleting nodes.
The change in interface_hanlers.c is only a comment to explain
how keymaps are being found.
- use NULL rather then 0 where possible (makes code & function calls more readable IMHO).
- set static variables and functions (exposed some unused vars/funcs).
- use func(void) rather then func() for definitions.
When using masks or other simple 3D elements in composites, doing
a layer re-rendering on a node is a bit clumsy all the time.
This commit does two things to help:
- new hotkey "Z" in node editor automatically finds render layer
that changed and re-renders it + composites
- option "Auto Render" does same, but then after every transform
edit in 3D window
The latter is experimental; real & proper system for this requires
full threaded render support (like previews). But it works!
Demo file:
http://download.blender.org/demo/test/auto_composite.blend
Important fix:
After any render, all the render layers were tagged "changed", which
caused any edit to first totally recomposte everthing. Now it only
composites changes.
Implementation notes
- DAG scene flush now sets 'changed' flags in render layer nodes
- Added notifier for 'transform finished' to trigger the update,
this is temporarily.
- values were added to both the classes __dict__ as well as the internal StructRNA.
- made properties available from the type since this is where the python api assigns them:
>>> bpy.types.Scene.frame_start
<bpy_struct, IntProperty("frame_start")>
- rename RNA_struct_type_properties() -> RNA_struct_type_properties(), added RNA_struct_type_find_property()
- On each re-render, the node image was cleared. Skipping this gives
nicer pictures
- Node render was using AA, but unfortunately only 1 sample for Nodes
is being stored. Disable AA render for now, nice speedup too.
compositor
Now ungrouping grouped-nodes copies the animation back to the main
nodetree. This means that it is now possible to successfully roundtrip
group/un-group nodes and their animation data.
---
This should also be done for the Separate Armature operator... hmm...
compositor
This commit fixes the original bug reported here by adding some
methods to move the relevant F-Curves (and drivers) over to the new
Node-Tree's (i.e. group-node) AnimData. Animated nodes which
subsequently get grouped will still be able to animate as a result of
this commit.
TODO's:
- Ungrouping now will not yet merge the animation back (or at least
copy it)
- Buttons for nodes freshly grouped do not correctly show animated
status indicators for some reason, yet normal animation does
Compositor: Texture node didn't use texture-nodes itself.
Now composites initialize texture nodes correctly.
Also reviewed the fix for crashing texture nodes for displace.
It appears texture nodes also are used for sculpt/paint
brushes, in these cases it can be allowed again. But, don't
do this during rendering for now!
Code cleanup to allow switching active output nodes in Compositor
made shader nodes output not set correctly.
Now you can have multiple output nodes in shaders too, and switch
on click-activate.
Preview render for node shaders broke, caused by localizing
materials last week, to prevent thread crashes. Fixed now.
Also added a temp fix to draw color-management corrected
node previews default. Will follow scene setting tomorrow.
Also: SSS in nodes doesn't render yet. Was issue in 2.4 too...
An error seems to have been introduced to the node-tree building at some point, which means that the ID-type for data-attached node trees was incorrect (i.e. scene->nodetree->id.name = NTREE_COMPOSIT instead of ID_NT).
This in turn meant that the ID AnimData availability poll would fail, as the ID-type could not be determined.
