This expose the capability of handling offscreen drawing. The initial
support lays the barebones for addons to work with framebuffer objects
and implement 3d viewport offscreen drawing. This can be used by script
writers to make fisheye lens preview, head mounted display support, ...
The complete documentation is here: http://www.blender.org/api/blender_python_api_2_76_1/gpu.offscreen.html
Review and many changes by Campbell Barton (thank you :)
https://developer.blender.org/D1533
The issue was caused by some special tricks needed to compile OpenSubdiv shader
which was using stupid check whether geometry shader is used or not.
Now made it more explicit call whether special OpenSubdiv trickery is needed or
not.
Its not ideal solution, but it's not really easy to do a proper solution for
this, because while we can do half of the work with if-defs in the shader code
but we'll still need to somewhat define layout of the input blocks which isn't
really doable with current shader version we're using.
support is missing.
Supporting those (really) old GPUs requires us to make shaders more
expensive by converting between real and scaled coordinates and be wary
of such conversion caveats when handling uv coordinates in shaders. Not
worth the cost for supporting hardware that old.
non-power-of-2 texture support. Note that all I did was pass
the correct width/height into glReadPixels; the result may not
be the same as if non2 textures were enabled.
I can't reproduce issue here but crash is most likely caused by passing
a NULL pointer to glUniform2fv.
This is caused by OpenSubdiv changes to the codegen module, which pass
mtex layers to the uniform system
even when not needed.
Since Sergey is demoing OpenSubdiv in a few days, I'll
go with the easy fix for now which is just checking for NULL pointer, but
this needs to be fixed properly at some point.
Use OpenGL 3.2 extension ARB_draw_elements_base_vertex, which allows us
to add offset in index buffer indices automatically. This should reduce
the number of draw calls significantly.
We may have some errors on the Mac with VBO setting off.
OSX OpenGL extensions don't play well with vertex arrays.
Will test that more later.
We might also use a full element buffer here, like we do when hiding
some quads, but this approach keeps the memory savings intended
originally.
Was overdrawing the buffer, in case of fast drawing just use one
draw call. Should also make performance quite smoother.
Note:
Just discovered we are doing one draw call - per grid - in multires
apparently to keep reusing the same element buffer.
This is horribly, dreadfully slow and will check about fixing it later.
Also the refactor exposed an error where we requested too much
memory from the video memory in general for all mesh types.
Now we are back to normal :)
I suspect code here can be cleaned up but for now try this.
Alternatively we can check for errors around buffer allocation
but this needs bigger changes.
properly.
This should fix failure to use vertex arrays in OSX with high
polycounts.
Note this will not suffice as a fix when we move to VBOs exclusively
(GL 3+), we'll have to think of some way to separate huge meshes to many
VBOs.
This commit contains all the remained parts needed for initial integration of
OpenSubdiv into Blender's subdivision surface code. Includes both GPU and CPU
backends which works in the following way:
- When SubSurf modifier is the last in the modifiers stack then GPU pipeline
of OpenSubdiv is used, making viewport performance as fast as possible.
This also requires graphscard with GLSL 1.5 support. If this requirement is
not met, then no GPU pipeline is used at all.
- If SubSurf is not a last modifier or if DerivesMesh is being evaluated for
rendering then CPU limit evaluation API from OpenSubdiv is used. This only
replaces the legacy evaluation code from CCGSubSurf_legacy, but keeps CCG
structures exactly the same as they used to be for ages now.
This integration is fully covered with ifdef and not enabled by default
because there are several TODOs to be solved first:
- Face varying data interpolation is not really cleanly implemented for GPU
in OpenSubdiv 3.0. It is also not implemented for limit evaluation API.
This basically means we'll have really hard time supporting UVs.
- Limit evaluation only works with adaptivly subdivided meshes so far, which
basically means all the points of CCG are pushed to the limit. This gives
different result from old code.
- There are some serious optimizations possible on the topology refiner
creation, which would speed up initial OpenSubdiv mesh creation.
- There are some hardcoded asumptions in the GPU and DerivedMesh areas which
could be generalized.
That's something where Antony and Campbell can help, making it so the code
is structured in a way which is reusable by all planned viewport projects.
- There are also some workarounds in the dependency graph to make sure OpenGL
buffers are only freed from the main thread.
Those who'll be wanting to make experiments with this code should grab dev
branch (NOT master) from
https://github.com/Nazg-Gul/OpenSubdiv/tree/dev
There are some patches applied in there which we're working on on getting
into upstream.
This stores loop indices into the loop array giving easier acess
to data such as vertex-colors and UV's,
removing the need to store an MFace duplicate of custom-data.
This doesn't yet move all internal code from MFace to LoopTri just yet.
Only applies to:
- opengl drawing
- sculpting (pbvh)
- vertex/weight paint
Thanks to @psy-fi for review, fixes and improvements to drawing!
Remove legacy code completely, now dyntopo, multires et al even work on
GL 1.1 for really hardcore users :p
Real purpose here though is to be able to have fast multires drawing
even with VBO off, since it requires using indices for vertex buffers.
Also made own code elf puke an eaten normal update function which
made multires not update normals in solid mode...sorry.
Get rid of legacy drawing, it's only used for selection,
in which case we can prepare a temporary color buffer and draw
at once. Code is not complete here because we still redundantly
set the draw color in the draw function and don't ommit hidden
faces automatically. Still it works 100% without immediate mode
now.
