Move the weight paint drawing to the fragment shader. The shader
uses a texture that uses the U.coba_weight custom color band, or
an internal color band.
In addition to actual weights, the shader has to display two
alert colors: missing vertex group, and zero weight. The zero
weight alert has to be blended with regular weight colors,
so that a single alert vertex surrounded by weighted ones is
still visible.
Reviewers: campbellbarton, fclem
Differential Revision: https://developer.blender.org/D3675
This does not fix the smokesim. It only port the drawing method.
The Object mode engine is in charge of rendering the velocity debugging.
Things left to do:
- Flame rendering.
- Color Ramp coloring of volume data.
- View facing slicing (for now it's only doing sampling starting from the
volume bounds which gives a squarish look)
- Add option to enable dithering (currently on by default.
- Vertex size now matches the theme setting.
- Edge width is closer to a single pixel line.
- Face dot was scaled up to be drawn as a circle,
but is currently a square.
This commit restores support for Motion Path drawing in 2.8 (as it wasn't ported over
to the new draw engines earlier, and the existing space_view3d/drawanimviz.c code was
removed during the Blender Internal removal).
Notes:
* Motion Paths are now implemented as an overlay (enabled by default).
Therefore, you can turn all of them on/off from the "Overlays" popover
* By and large, we have kept the same draw style as was used in 2.7
Further changes can happen later following further design work.
* One change from 2.7 is that thicker lines are used by default (2px vs 1px)
Todo's:
* There are some bad-level calls introduced here (i.e. the actgroup_to_keylist() stuff).
These were introduced to optimise drawing performance (by avoiding full keyframes -> keylist
conversion step on each drawcall). Instead, this has been moved to the calculation step
(in blenkernel). Soon, there will be some cleanups/improvements with those functions,
so until then, we'll keep the bad level calls.
Credits:
* Clément Foucault (fclem) - Draw Engine magic + Shader Conversion/Optimisation
* Joshua Leung (Aligorith) - COW fixes, UI integration, etc.
Revision History:
See "tmp-b28-motionpath_drawing" branch (rBa12ab5b2ef49ccacae091ccb54d72de0d63f990d)
The actual code is a bit convoluted but allows good and "pseudo efficient"
drawing. (pseudo efficient because rendering instances with that amount of
vertices is really inneficient. We should go full procedural but need to
have bufferTexture implemented first) But drawing speed is not a bottleneck
here and it's already a million time less crappy than the old (2.79) immediate
mode method.
Instead of drawing actual wires with different width we render a triangle
fan batch (containing 3 fans: bone, head, tail) which is then oriented in
screen space to the bone direction. We then interpolate a float value
accross vertices giving us a nice blend factor to blend the colors and
gives us really smooth interpolation inside the bone.
The outside edge still being geometry will be antialiased by MSAA if enabled.
Now the axes are displayed correctly at the tip of the bone and with the
axes names.
I've made some modifications though:
- Axes are colored. (should not be in object mode but that's TODO)
- Axes ends are not flat arrows anymore. Replaced with a small diamond.
- Axes names are now scale by their respective axes instead of being
affected by other axes.
- Changed axes names "font" to be a bit more sexy.
This will enable us to do more nice stuff in future commits.
This commit is a temporary commit, it will compile but will crash if
trying to display any armature. Next commit does work.
The actual weighting calculation is not smooth as the bone display.
The bone itself can be smooth for esthetic purpose but the distance display
should match the underlying weighting formula.
We now use a more pleasant and efficient way to display enveloppe bones
and their radius.
For this we use a capsule geometry that is displaced (in the vertex shader)
to a signed distance field that represents the bone shape.
The bone distance radius are now drawn in 3D using a "pseudo-fresnel" effect.
This gives a better understanding of what is inside the radius of influence.
When capsules are not needed, we switch to default raytraced points.
The capsules are not distorded by the bone's matrix (same as their actual
influence radius) and are correctly displayed even with complex scaled
parents hierarchy.
Here is how it works:
We render a high poly disc that we orient & scale towards the camera so that
it covers the same pixel of the sphere it's supposed to represent.
Then the pixel shader raytrace the sphere (effectively starting from
the poly disc depth) and outputs the depth to gl_FragDepth.
This approach has many benefit:
- high quality obviously: per pixel accurate depth!
- compatible with MSAA: since the sphere horizon is delimited by polygons,
we get the coverage computed by the rasterizer. However we still gets
aliasing if the sphere intersect directly other meshes.
- virtually no overdraw: there is no backface to shade but we still get
overdraw because by little triangle [gpus rasterize pixel by groups of 4].
- allows early depth test: since the poly disc is set at the nearest depth
we can output, we can use GL_ARB_conservative_depth to enable early depth
test and discard pixels that are already behind geometry.
- can draw outline pretty easily without geometry shader.
This fix the issue with the zfighting we were getting at bones edges.
Moreover, this enables us to render arbitrarly large outline with
varying thickness.
Because:
- Less redundancy.
- Better suffixes.
Also a few modification to GPU_texture_create_* to simplify the API:
- make the format explicit to the texture creation process.
- remove the component count as it's specified in the GPUTextureFormat.
This removes the need of custom attribs for instancing.
Instancing works fully with dynamic batches & Gwn_VertFormat now.
This is in prevision of the VAO manager patch.
