Many parts of the compositor are unnecessarily complicated. This patch
aims at reducing the complexity of writing nodes and making the code
more transparent.
== Separating Nodes and Operations ==
Currently these are both mixed in the same graph, even though they have
very different purposes and are used at distinct stages in the
compositing process. The patch introduces dedicated graph classes for
nodes and for operations.
This removes the need for a lot of special case checks (isOperation etc.)
and explicit type casts. It simplifies the code since it becomes clear
at every stage what type of node we are dealing with. The compiler can
use static typing to avoid common bugs from mixing up these types and
fewer runtime sanity checks are needed.
== Simplified Node Conversion ==
Converting nodes to operations was previously based on "relinking", i.e.
nodes would start with by mirroring links in the Blender DNA node trees,
then add operations and redirect these links to them. This was very hard
to follow in many cases and required a lot of attention to avoid invalid
states.
Now there is a helper class called the NodeConverter, which is passed to
nodes and implements a much simpler API for this process. Nodes can add
operations and explicit connections as before, but defining "external"
links to the inputs/outputs of the original node now uses mapping
instead of directly modifying link data. Input data (node graph) and
result (operations graph) are cleanly separated.
== Removed Redundant Data Structures ==
A few redundant data structures have been removed, notably the
SocketConnection. These are only needed temporarily during graph
construction. For executing the compositor operations it is perfectly
sufficient to store only the direct input link pointers. A common
pointer indirection is avoided this way (which might also give a little
performance improvement).
== Avoid virtual recursive functions ==
Recursive virtual functions are evil. They are very hard to follow
during debugging. At least in the parts this patch is concerned with
these functions have been replaced by a non-virtual recursive core
function (which might then call virtual non-recursive functions if
needed). See for example NodeOperationBuilder::group_operations.
The issue was caused by the readEWA spending loads of time trying
to sample regions outside of the buffer.Solved by adding an early
exit check.
We could also clamp the sampling region to the rect, but it's
not so much clear whether weight will be correct in such case
so left it for the future.
This was suggested by Christopher Barrett (terrachild). Corner pin is a common feature in compositing.
The corners for the plane warping can be defined by using vector node inputs to allow using perspective plane transformations without having to go via the MovieClip editor tracking data.
Uses the same math as the PlaneTrack node, but without the link to MovieClip and Object.
{F78199}
The code for PlaneTrack operations has been restructured a bit to share it with the CornerPin node.
* PlaneDistortCommonOperation.h/.cpp: Shared generic code for warping images based on 4 plane corners and a perspective matrix generated from these. Contains operation base classes for both the WarpImage and Mask operations.
* PlaneTrackOperation.h/.cpp: Current plane track node operations, based on the common code above. These add pointers to MovieClip and Object which define the track data from wich to read the corners.
* PlaneCornerPinOperation.h/.cpp: New corner pin variant, using explicit input sockets for the plane corners.
One downside of the current compositor design is that there is no concept of invariables (constants) that don't vary over the image space. This has already been an issue for Blur nodes (size input is usually constant except when "variable size" is enabled) and a few others. For the corner pin node it is necessary that the corner input sockets are also invariant. They have to be evaluated for each tile now, otherwise the data is not available. This in turn makes it necessary to make the operation "complex" and request full input buffers, which adds unnecessary overhead.
nodes (Blur) causes crash due to chained read/write buffer operations.
The way read/write buffer operations are created for both the wrapped
translate node and then the "complex" blur node creates a chain of
buffers in the same ExecutionGroup. This leaves the later write buffer
operations without a proper "executor" group and fails on assert.
Solution for now is to check for existing output buffer operations like
it already happens for inputs. This is extremely ugly code, but should
become a lot more transparent after compositor cleanup ({D309}).
As discussed in T38340 the solution is to use the current scene from
context whenever feasible.
Composite does not use node->id at all now, the scene which owns the
compositing node tree is retrieved from context instead.
Defocus node->id is made editable by the user. By default it is not set,
which also will make it use the contextual scene and camera info.
The node->id pointer in Defocus is **not** cleared in older blend files.
This is done for backward compatibility: the node will then behave as
before in untouched scenes.
File Output nodes also don't store scene in node->id. This is only needed
when creating a new node for initializing the file format.
Reviewers: brecht, jbakker, mdewanchand
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D290
EWA sampling is designed for downsampling images, i.e. scaling down the size of
input image pixels, which happens regularly in compositing. While the standard
sampling methods (linear, cubic) work reasonably well for linear
transformations, they don't yield good results in non-linear cases like
perspective projection or arbitrary displacement. EWA sampling is comparable to
mipmapping, but avoids problems with discontinuities.
To work correctly the EWA algorithm needs partial derivatives of the mapping
functions which convert output pixel coordinates back into the input image
space (2x2 Jacobian matrix). With these derivatives the EWA algorithm
projects ellipses into the input space and accumulates colors over their
area. This calculation was not done correctly in the compositor, only the
derivatives du/dx and dv/dy were calculation, basically this means it only
worked for non-rotated input images.
The patch introduces full derivative calculations du/dx, du/dy, dv/dx, dv/dy for
the 3 nodes which use EWA sampling currently: PlaneTrackWarp, MapUV and
Displace. In addition the calculation of ellipsis area and axis-aligned
bounding boxes has been fixed.
For the MapUV and Displace nodes the derivatives have to be estimated by
evaluating the UV/displacement inputs with 1-pixel offsets, which can still have
problems on discontinuities and sub-pixel variations. These potential problems
can only be alleviated by more radical design changes in the compositor
functions, which are out of scope for now. Basically the values passed to the
UV/Displacement inputs would need to be associated with their 1st order
derivatives, which requires a general approach to derivatives in all nodes.
Changes for VC2013
Now, I can build Blender with VC2013 with Cycles, Collada, OpenExr,OpenImageIO disabled. Also, you need VC2008 sp1 installed to make old libs compatible.
Distinguish the 3 different methods for acquiring pixel color values (executePixel, executePixelSampled, executePixelFiltered).
This makes it easier to keep track of the different sampling methods (and works nicer with IDEs that do code parsing).
Differential Revision: http://developer.blender.org/D7
This was own error in r60049 which fixed chunk number calculation. This was mixing int and unsigned int values from ExecutionGroup, which leads to huge chunk numbers which are then skipped.
Debug code for graphviz output moved to a dedicated file COM_Debug.h/cpp.
The DebugInfo class has only static functions, which are called from a number of places to keep track of what is happening in the compositor. If debugging is disabled these are just inline stubs, so we
don't need #ifdefs everywhere and don't get any overhead.
The graphviz output is much more useful now. DebugInfo keeps track of node names in a static string map for meaningful names. It uses a number of colors for various special operation classes.
ExecutionGroups are indicated in graphviz with clusters.
Currently the graphviz .dot files are stored in the BLI_temporary_dir() folder. A separate dot file is generated for each stage of the ExecutionGroup scheduling, this is intended to give some idea of the
compositor progress, but could still be improved.
The chunk indices for scheduling chunks based on a given area were calculated incorrectly. This caused chunks at the very border of the render (pixels 256..257) to be omitted, leading to incorrect values
in the Z buffer of the test file, which in turn caused wrong normalization range and the resulting almost-white image.
Also added a dedicated executePixel function for Z buffer to avoid any interpolation of Z values.
- add missing headers from cmake (own omission)
- quiet rna_test.c unused define warnings.
- minor style edits
- spelling corrections and ignore all uppercase words with spell checking script.
It was caused by wrong copy-paste thing, which replaced check
"whether alpha channel is enabled" with "whether alpha channel
is not zero" (which is always zero in accumulator).
Compositor always works with RGBA, so no need to do any special
checks here.
TODO: Maybe MapUV ode shall ignore alpha channel?
This commit includes all the changes made for plane tracker
in tomato branch.
Movie clip editor changes:
- Artist might create a plane track out of multiple point
tracks which belongs to the same track (minimum amount of
point tracks is 4, maximum is not actually limited).
When new plane track is added, it's getting "tracked"
across all point tracks, which makes it stick to the same
plane point tracks belong to.
- After plane track was added, it need to be manually adjusted
in a way it covers feature one might to mask/replace.
General transform tools (G, R, S) or sliding corners with
a mouse could be sued for this. Plane corner which
corresponds to left bottom image corner has got X/Y axis
on it (red is for X axis, green for Y).
- Re-adjusting plane corners makes plane to be "re-tracked"
for the frames sequence between current frame and next
and previous keyframes.
- Kayframes might be removed from the plane, using Shit-X
(Marker Delete) operator. However, currently manual
re-adjustment or "re-track" trigger is needed.
Compositor changes:
- Added new node called Plane Track Deform.
- User selects which plane track to use (for this he need
to select movie clip datablock, object and track names).
- Node gets an image input, which need to be warped into
the plane.
- Node outputs:
* Input image warped into the plane.
* Plane, rasterized to a mask.
Masking changes:
- Mask points might be parented to a plane track, which
makes this point deforming in a way as if it belongs
to the tracked plane.
Some video tutorials are available:
- Coder video: http://www.youtube.com/watch?v=vISEwqNHqe4
- Artist video: https://vimeo.com/71727578
This is mine and Keir's holiday code project :)
- fix thumbnail preview (previously it showed only one input)
- make SplitViewer node update even if the second input is not connected
- now it works when the first socket is connected to a zero-sized node tree (e. g. Color Input node)
- SplitViewer node is now based on 2 operations: SplitOperation and ViewerOperation.
- ViewerBaseOperation was removed as a redundant one. Any future viewer style node can use the same principle and prepare the output before passing to an actual ViewerOperation.
Thanks Lukas Toenne for reviewing this patch and giving me get few pieces of advice.
Issue was caused by file output node actually,
The thing here is, compositor output does have fixed
resolution and we could predict how to map coordinates
for border and cropping in that case.
But viewers and file output nodes are currently totally
depending on an input resolution. Could not see how
border could be applied reliably in this cases.
Disabling border option for file output node, so
now it shall behave the same way as it was before.
Discovered issues when using cropping to render border,
namely there's an offset in viewer nodes and previews,
but this is separate issue i guess (file output seems
to work fine). Will revisit this issue in next days.
The design changes coming with pynodes for the node editor allow editing multiple node groups or pinning. This is great for working on different node groups without switching between them all the time, but it causes a problem for viewer nodes: these nodes all write to the same Image data by design, causing access conflicts and in some cases memory corruption. This was not a problem before pynodes because the editor would only allow 1 edited node group at any time. With the new flexibility of node editors this restriction is gone.
In order to avoid concurrent write access to the viewer image buffer and resolve the ambiguity this patch adds an "active viewer key" to the scene->nodetree (added in bNodeTree instead of Scene due to otherwise circular DNA includes). This key identifies a specific node tree/group instance, which enables the compositor to selectively enable only 1 viewer node.
The active viewer key is switched when opening/closing node groups (push/pop on the snode->treepath stack) or when selecting a viewer node. This way only the "last edited" viewer will be active.
Eventually it would be nicer if each viewer had its own buffer per node space so one could actually compare viewers without switching. But that is a major redesign of viewer nodes and images, not a quick fix for bcon4 ...
- pass string size to BLI_timestr() to avoid possible buffer overrun.
- quiet warning for mingw.
- include guards for windows utf conversion funcs.
- fix for mistage in edge-angle-selection check.
- some style cleanup.
