Commit Graph

2216 Commits

Author SHA1 Message Date
Jeroen Bakker
5f749a03ca Fix T88456: DrawManager: Keep subset RenderMeshData around when geometry does not change.
Reuse loose geometry during selection (and other operations) from
previous calculation. Loose geometry stays the same, but was
recalculated to determine the size of GPU buffers. This patch would
reuse the previous loose geometry when geometry wasn't changed.

Although not the main bottleneck during selection it is measurable.

Master.
`rdata 46ms iter 55ms (frame 410ms)`

This patch.
`rdata 5ms iter 52ms (frame 342ms)`

Reviewed By: mano-wii

Differential Revision: https://developer.blender.org/D11339
2021-05-31 09:33:31 +02:00
Clément Foucault
5b8a41d387 Merge branch 'blender-v2.93-release' 2021-05-28 18:19:07 +02:00
Clément Foucault
c369382977 EEVEE: Fix NaN caused by ensure_valid_reflection()
This was caused by unsafe sqrt calls.

Fixes T86578 white artifacts in EEVEE

Reviewed By: brecht, dfelinto

Differential Revision: https://developer.blender.org/D11428
2021-05-28 18:16:56 +02:00
Germano Cavalcante
c65f4b3d76 DrawManager: Early return for buffer cache creation
No real functional changes.

This is useful for benchmark cases when `cache->uv_cage` is passed but
has no buffers are requested.
2021-05-28 11:51:13 -03:00
Jeroen Bakker
6b03621c01 DrawManager: Use Compute Shader to Update Hair.
This patch will use compute shaders to create the VBO for hair.
The previous implementation uses transform feedback.

Timings before: between 0.000069s and 0.000362s.
Timings after:  between 0.000032s and 0.000092s.

Speedup isn't noticeable by end-users. The patch is used to test
the new compute shader pipeline and integrate it with the draw
manager. Allowing EEVEE, Workbench and other draw engines to
use compute shaders with the introduction of `DRW_shgroup_call_compute`
and `DRW_shgroup_vertex_buffer`.

Future improvements are possible by generating the index buffer
of hair directly on the GPU.

NOTE: that compute shaders aren't supported by Apple and still use
the transform feedback workaround.

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D11057
2021-05-28 08:16:26 +02:00
Hans Goudey
ac833108db Geometry Nodes: Draw curve data in the viewport
This patch adds relatively small changes to the curve draw
cache implementation in order to draw the curve data in the
viewport. The dependency graph iterator is also modified
so that it iterates over the curve geometry component, which
is presented to users as `Curve` data with a pointer to the
`CurveEval`

The idea with the spline data type in geometry nodes is that
curve data itself is only the control points, and any evaluated
data with faces is a mesh. That is mostly expected elsewhere in
Blender anyway. This means it's only necessary to implement
wire edge drawing of `CurveEval` data.

Adding a `CurveEval` pointer to `Curve` is in line with changes
I'd like to make in the future like using `CurveEval` in more places
such as edit mode.

An alternate solution involves converting the curve wire data
to a mesh, however, that requires copying all of the data, and
since avoiding it is rather simple and is in-line with future plans
anyway, I think doing it this way is better.

Differential Revision: https://developer.blender.org/D11351
2021-05-27 10:08:40 -04:00
Germano Cavalcante
6fc9ec9257 Cleanup: Specify amount of buffers through preprocessor directives 2021-05-26 22:52:59 -03:00
Jeroen Bakker
2c607ec2f6 Revert "DrawManager: Use Compute Shader to Update Hair."
This reverts commit 8f9599d17e.

Mac seems to have an error with this change.
```
                 ERROR: /Users/blender/git/blender-vdev/blender.git/source/blender/draw/intern/draw_hair.c:115:44: error: use of undeclared identifier 'shader_src'
                 ERROR: /Users/blender/git/blender-vdev/blender.git/source/blender/draw/intern/draw_hair.c:123:13: error: use of undeclared identifier 'shader_src'
                 ERROR: make[2]: *** [source/blender/draw/CMakeFiles/bf_draw.dir/intern/draw_hair.c.o] Error 1
                 ERROR: make[1]: *** [source/blender/draw/CMakeFiles/bf_draw.dir/all] Error 2
                 ERROR: make: *** [all] Error 2

```
2021-05-26 20:32:05 +02:00
Jeroen Bakker
8f9599d17e DrawManager: Use Compute Shader to Update Hair.
This patch will use compute shaders to create the VBO for hair.
The previous implementation uses tranform feedback.

Timings master (transform feedback with GPU_USAGE_STATIC between 0.000069s and 0.000362s
Timings transform feedback with GPU_USAGE_DEVICE_ONLY. between 0.000057s and 0.000122s
Timings compute shader between 0.000032 and 0.000092s

Future improvements:
* Generate hair Index buffer using compute shaders: currently done single threaded on CPU, easy to add as compute shader.

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D11057
2021-05-26 17:03:37 +02:00
Jeroen Bakker
87055dc71b GPU: Compute Pipeline.
With the compute pipeline calculation can be offloaded to the GPU.
This patch only adds the framework for compute. So no changes for users at
this moment.

NOTE: As this is an OpenGL4.3 feature it must always have a fallback.

Use `GPU_compute_shader_support` to check if compute pipeline can be used.
Check `gpu_shader_compute*` test cases for usage.

This patch also adds support for shader storage buffer objects and device only
vertex/index buffers.

An alternative that had been discussed was adding this to the `GPUBatch`, this
was eventually not chosen as it would lead to more code when used as part of a
shading group. The idea is that we add an `eDRWCommandType` in the near
future.

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D10913
2021-05-26 16:49:30 +02:00
Hans Goudey
c0bb7d9cb7 Cleanup: Fix short comparison with bool warning
For some reason the hide status is stored in a short and a char
(we cannot have bools in DNA).
2021-05-25 14:37:58 -04:00
Jeroen Bakker
cb8a6814fd Blenlib: Explicit Colors.
Colors are often thought of as being 4 values that make up that can make any color.
But that is of course too limited. In C we didn’t spend time to annotate what we meant
when using colors.

Recently `BLI_color.hh` was made to facilitate color structures in CPP. CPP has possibilities to
enforce annotating structures during compilation and can adds conversions between them using
function overloading and explicit constructors.

The storage structs can hold 4 channels (r, g, b and a).

Usage:

Convert a theme byte color to a linearrgb premultiplied.
```
ColorTheme4b theme_color;
ColorSceneLinear4f<eAlpha::Premultiplied> linearrgb_color =
    BLI_color_convert_to_scene_linear(theme_color).premultiply_alpha();
```

The API is structured to make most use of inlining. Most notable are space
conversions done via `BLI_color_convert_to*` functions.

- Conversions between spaces (theme <=> scene linear) should always be done by
  invoking the `BLI_color_convert_to*` methods.
- Encoding colors (compressing to store colors inside a less precision storage)
  should be done by invoking the `encode` and `decode` methods.
- Changing alpha association should be done by invoking `premultiply_alpha` or
  `unpremultiply_alpha` methods.

# Encoding.

Color encoding is used to store colors with less precision as in using `uint8_t` in
stead of `float`. This encoding is supported for `eSpace::SceneLinear`.
To make this clear to the developer the `eSpace::SceneLinearByteEncoded`
space is added.

# Precision

Colors can be stored using `uint8_t` or `float` colors. The conversion
between the two precisions are available as methods. (`to_4b` and
`to_4f`).

# Alpha conversion

Alpha conversion is only supported in SceneLinear space.

Extending:
- This file can be extended with `ColorHex/Hsl/Hsv` for different representations
  of rgb based colors. `ColorHsl4f<eSpace::SceneLinear, eAlpha::Premultiplied>`
- Add non RGB spaces/storages ColorXyz.

Reviewed By: JacquesLucke, brecht

Differential Revision: https://developer.blender.org/D10978
2021-05-25 17:16:54 +02:00
Jeroen Bakker
00955cd31e Revert "Blenlib: Explicit Colors."
This reverts commit fd94e03344.
does not compile against latest master.
2021-05-25 17:03:54 +02:00
Jeroen Bakker
fd94e03344 Blenlib: Explicit Colors.
Colors are often thought of as being 4 values that make up that can make any color.
But that is of course too limited. In C we didn’t spend time to annotate what we meant
when using colors.

Recently `BLI_color.hh` was made to facilitate color structures in CPP. CPP has possibilities to
enforce annotating structures during compilation and can adds conversions between them using
function overloading and explicit constructors.

The storage structs can hold 4 channels (r, g, b and a).

Usage:

Convert a theme byte color to a linearrgb premultiplied.
```
ColorTheme4b theme_color;
ColorSceneLinear4f<eAlpha::Premultiplied> linearrgb_color =
    BLI_color_convert_to_scene_linear(theme_color).premultiply_alpha();
```

The API is structured to make most use of inlining. Most notable are space
conversions done via `BLI_color_convert_to*` functions.

- Conversions between spaces (theme <=> scene linear) should always be done by
  invoking the `BLI_color_convert_to*` methods.
- Encoding colors (compressing to store colors inside a less precision storage)
  should be done by invoking the `encode` and `decode` methods.
- Changing alpha association should be done by invoking `premultiply_alpha` or
  `unpremultiply_alpha` methods.

# Encoding.

Color encoding is used to store colors with less precision as in using `uint8_t` in
stead of `float`. This encoding is supported for `eSpace::SceneLinear`.
To make this clear to the developer the `eSpace::SceneLinearByteEncoded`
space is added.

# Precision

Colors can be stored using `uint8_t` or `float` colors. The conversion
between the two precisions are available as methods. (`to_4b` and
`to_4f`).

# Alpha conversion

Alpha conversion is only supported in SceneLinear space.

Extending:
- This file can be extended with `ColorHex/Hsl/Hsv` for different representations
  of rgb based colors. `ColorHsl4f<eSpace::SceneLinear, eAlpha::Premultiplied>`
- Add non RGB spaces/storages ColorXyz.

Reviewed By: JacquesLucke, brecht

Differential Revision: https://developer.blender.org/D10978
2021-05-25 17:01:26 +02:00
Hans Goudey
2175cbe2ce Cleanup: Move curve draw cache implementation to C++
I'd like to use this file to draw curves from geometry nodes, which
would otherwise require implementing a C API. The changes in this
commit are minimal, mostly just casts and changing to nullptr.

Differential Revision: https://developer.blender.org/D11350
2021-05-21 17:28:29 -04:00
Antonio Vazquez
ef04fd9571 GPencil: Fix missing annotations in VSE strip
Since version 2.80, the annotations of the Scene strip were not displayed in VSE. Also, the UI panel was`Grease Pencil` and must be `Annotation`

The problem was the offscreen render hasn't evil_CTX and the section of the annotation was never called.

Differential Revision: https://developer.blender.org/D11329
2021-05-20 20:16:59 +02:00
Jacques Lucke
1a81d268a1 Materials: support changing materials during evaluation
This commit allows that the evaluated geometry of an object has
different materials from the original geometry. This is needed
for geometry nodes.

The main thing that changes for render engines and exporters
is that the number of material slots on an object and its geometry
might not match anymore. For original data, the slot counts are
still equal, but not for evaluated data.

Accessing material slots though rna stays the same. The behavior
adapts automatically depending on whether the object is evaluated.

When accessing materials of an object through `BKE_object_material_*`
one has to use a new api for evaluated objects:
`BKE_object_material_get_eval` and `BKE_object_material_count_eval`.
In the future, the different behavior might be hidden behind a more
general C api, but that would require quite a few more changes.

The ground truth for the number of materials is the number of materials
on the geometry now. This is important in the current design, because
Eevee needs to know the number of materials just based on the mesh in
`mesh_render_mat_len_get` and similar places.

In a few places I had to add a special case for mesh edit mode to get it
to work properly. This is unfortunate, but I don't see a way around that
for now.

Differential Revision: https://developer.blender.org/D11236
2021-05-19 10:23:09 +02:00
Richard Antalik
89bc6b5508 Merge branch 'blender-v2.93-release' 2021-05-05 07:22:10 +02:00
Clément Foucault
96abe5ebbc DRW: Fix issue with batch reusing freed VBO indices.
Some discard of vertbuf were not correctly followed by discards of
the GPUBatches that were using them. This lead to a use-after-free
situation where GPUBatches would reuse old VBO information. This did
not crash immediatly because the VBO indices were cached by our VAO
caching system. It kept working on some implementation because VBO
reference in the VAO (probably) preventing the VBO from being freed
by reference counting.

This fixes T85977 NVidia: Random crashes in 'DrvPresentBuffers'
2021-05-04 22:58:43 +02:00
Campbell Barton
8a1d3bf2b1 Merge branch 'blender-v2.93-release' 2021-04-30 15:16:08 +10:00
Campbell Barton
d6b26b3fa0 Fix potential buffer overrun in drw_shader_dependencies_get
Logical error let this function to write one past the buffer bounds.
2021-04-30 15:08:28 +10:00
Falk David
183e3f6bb9 Fix T86968: Last UV factor in cyclic strokes
The UV factor of the last point of a cyclic stroke was using the factor of
the first point leading to unwanted scaling artifacts.

The fix sets the uv factor of the last point to the currect value (last UV
factor + length between last and first point).

Reviewed By: antoniov, fclem

Maniphest Tasks: T86968

Differential Revision: https://developer.blender.org/D10850
2021-04-21 12:16:32 +02:00
Clément Foucault
4cf60a2abf Fix T87369 EEVEE: Ambient Oclussion: Firefly caused by degenerated normal
This was caused by some sort of degenerated normals.
2021-04-20 16:07:45 +02:00
Clément Foucault
27cfc1ea11 Fix T87541 EEVEE: AO causes black outline around objects and NaN pixels
It seems the pow result is unstable on some implementations.

Also avoid undefined behavior by clamping aoFactor to strict positive values.
2021-04-20 10:59:07 +02:00
Philipp Oeser
2110239547 Fix T87150: bad points appearance in orthographic view
Points are drawn as half octahedron (aligned to the camera).
Getting the appropriate matrix for facing the camera would fail in in
orthographic view, points were not facing the camera (revealing their
missing other half octahedron)

Maniphest Tasks: T87150

Differential Revision: https://developer.blender.org/D10923
2021-04-09 09:14:53 +02:00
Hans Goudey
fd414b4906 Cleanup: Use const arguments for volume code
The problem was that you could getting write access to a grid from a
`const Volume *` without breaking const correctness. I encountered this
when working on support for volumes in the bounding box node. For
geometry nodes there is an important distinction between getting data
"for read" and "for write", with the former returning a `const` version
of the data.

Also, for volumes it was necessary to cast away const, since all of
the relevant functions in `volume.cc` didn't have const versions. This
patch adds `const` in these places, distinguising between "for read"
and "for write" versions of functions where necessary.

The downside is that loading and unloading in the global volume cache
needs const write-access to some member variables. I see that as an
inherent problem that comes up with caching that never has a beautiful
solution anyway.

Some of the const-ness could probably be propogated futher in EEVEE
code, but I'll leave that out, since there is another level of caching.

Differential Revision: https://developer.blender.org/D10916
2021-04-08 12:00:26 -05:00
Sebastian Parborg
fa9b05149c Fix T84520: Make the different weight paint code paths exclusive to each other
Before this change, you could have the new sculpt symmetry code and the
older weight paint symmetry code active at the same time. This would
lead to users easily trashing their weigh paint data if they were not
careful when switching between modes.

Now the specific weight paint symmetry code is an exclusive toggle so
the user can't accidentally mirror strokes and vertex groups at the same
time. This also paves the way of supporting Y and Z symmetry in the
future for weight groups mirroring if we decide to add it in the future.

Reviewed By: Sybren

Differential Revision: http://developer.blender.org/D10426
2021-04-02 14:44:26 +02:00
Germano Cavalcante
1425411249 Cleanup/Refactor: Unify functions that redraw the depth buffer
Now `ED_view3d_backbuf_depth_validate`, `ED_view3d_draw_depth` and
`ED_view3d_draw_depth_gpencil` are unified in `ED_view3d_depth_override`.

This new function replaces `ED_view3d_autodist_init`.

Also, since `ED_view3d_depth_update` depends on the render context, and
changing the context is a slow operation, that function also was removed,
and the depth buffer cached is now updated inside the new unified drawing
function when the "bool update_cache" parameter is true.

Finally `V3D_INVALID_BACKBUF` flag has been renamed and moved to
`runtime.flag`.

Differential revision: https://developer.blender.org/D10678
2021-03-30 16:23:58 -03:00
Philipp Oeser
aeff59073b Fix T86219: Compositor backdrop not using Color Management View
Transforms in certain cases

This was caused by wrong flag checking in {rB278011e44d43}, which just
seems to be a copy-paste error.

For example, enabeling 'Auto-Offset' in the View menu would lead to CM
being ignored.

Maniphest Tasks: T86219

Differential Revision: https://developer.blender.org/D10751
2021-03-18 09:16:58 +01:00
Campbell Barton
bb6765f28f Cleanup: spelling 2021-03-18 09:36:44 +11:00
Clément Foucault
4e236326c1 EEVEE: Contact Shadow: Fix self intersection issues
This was cause by the change of some epsilon values for reflections.

This commit changes the planar reflection tracing to have correct
handling of parallel rays and discard any self intersection with normal
screen raytrace.
2021-03-15 15:52:02 +01:00
Clément Foucault
6a7f6f2867 Cleanup: EEVEE: Remove hammersley texture and split hammersley code 2021-03-13 20:59:20 +01:00
Germano Cavalcante
cfd7b4d1cd BLI: New 'BLI_array_iter_spiral_square'
No functional changes.

This function replaces some of the logic in
`DRW_select_buffer_find_nearest_to_point` that traverses a buffer in a
spiral way to search for a closer pixel (not the closest).

Differential Revision: https://developer.blender.org/D10548
2021-03-09 16:03:56 -03:00
Clément Foucault
ba75ea8012 EEVEE: Use Fullscreen maxZBuffer instead of halfres
This removes the need for per mipmap scalling factor and trilinear interpolation
issues. We pad the texture so that all mipmaps have pixels in the next mip.

This simplifies the downsampling shader too.

This also change the SSR radiance buffer as well in the same fashion.
2021-03-08 17:25:16 +01:00
Jacques Lucke
3de5fbba3a Fix T86050: use material count from correct data block
See comment in code for more details.

Differential Revision: https://developer.blender.org/D10615
2021-03-04 15:27:33 +01:00
Campbell Barton
6aec6568a0 Cleanup: spelling, minor corrections
Also use doxygen comments for sculpt functions.
2021-03-03 06:20:27 +11:00
Jeroen Bakker
ca2044f72b Fix T86122: Performance Debug View Viewport Not Working
The performance debug menu isn't used that often anymore as render doc
also show the timings. This patch will make sure that enabling the
performance debug view (21) does not crash blender.
2021-03-02 14:27:52 +01:00
Clément Foucault
1d51cb6be2 Cleanup: EEVEE: change cameraVec macro to cameraVec(P)
This makes is clearer and avoid having to setup worldPosition if
shader is not a material shader.
2021-02-21 01:33:56 +01:00
Clément Foucault
6fa984a1af GPU: Add RGB10_A2 format support
Nice format to output high definition normals or normalized colors.
2021-02-21 01:33:56 +01:00
Clément Foucault
64d96f68d6 EEVEE: Ambient Occlusion: Refactor
- Fix noise/banding artifact on distant geometry.
- Fix overshadowing on un-occluded surfaces at grazing angle producing "fresnel"
  like shadowing. Some of it still appears but this is caused to the low number
  of horizons per pixel.
- Improve performance by using a fixed number of samples and fixing the
  sampling area size. A better sampling pattern is planned to recover
  the lost precision on large AO radius.
- Improved normal reconstruction for the AO pass.
- Improve Bent Normal reconstruction resulting in less faceted look on
  smoothed geometry.
- Add Thickness heuristic to avoid overshadowing of thin objects.
  Factor is currently hardcoded.
- Add bent normal support to Glossy reflections.
- Change Glossy occlusion to give less light leaks from lightprobes.
  It can overshadow on smooth surface but this should be mitigated by
  using SSR.
- Use Bent Normal for rough Glossy surfaces.
- Occlusion is now correctly evaluated for each BSDF. However this does make
  everything slower. This is mitigated by the fact the search is a lot faster
  than before.
2021-02-21 01:33:56 +01:00
Campbell Barton
7bb2b910c0 Cleanup: doxygen sections 2021-02-20 15:35:00 +11:00
Germano Cavalcante
89c79c3ed8 Cleanup: Abbreviate enums with 'UNSIGNED_' in the name 2021-02-17 12:38:21 -03:00
Campbell Barton
bfc7994d93 Cleanup: use edituv prefix for stretch area/angle data 2021-02-17 15:36:18 +11:00
Campbell Barton
2853ad775e Merge branch 'blender-v2.92-release' 2021-02-17 15:19:21 +11:00
Campbell Barton
6ce06957c9 Fix T85680: Crash displaying UV stretch/area with modifiers
This uses the same logic as drawing UV's,
where non-bmesh defaults to mesh.
2021-02-17 15:12:39 +11:00
Campbell Barton
62592af843 Cleanup: pass scene as const 2021-02-17 14:50:08 +11:00
Campbell Barton
3c1e70dedf Cleanup: spelling 2021-02-14 11:19:06 +11:00
Clément Foucault
7f7e683099 EEVEE: Refactor closure_lit_lib.glsl
This refactor was needed for some reasons:
- closure_lit_lib.glsl was unreadable and could not be easily extended to use new features.
- It was generating ~5K LOC for any shader. Slowing down compilation.
- Some calculations were incorrect and BSDF/Closure code had lots of workaround/hacks.

What this refactor does:
- Add some macros to define the light object loops / eval.
- Clear separation between each closures which now have separate files. Each closure implements the eval functions.
- Make principled BSDF a bit more correct in some cases (specular coloring, mix between glass and opaque).
- The BSDF term are applied outside of the eval function and on the whole lighting (was separated for lights before).
- Make light iteration last to avoid carrying more data than needed.
- Makes sure that all inputs are within correct ranges before evaluating the closures (use `safe_normalize` on normals).
- Making each BSDF isolated means that we might carry duplicated data (normals for instance) but this should be optimized by compilers.
- Makes Translucent BSDF its own closure type to avoid having to disable raytraced shadows using hacks.
- Separate transmission roughness is now working on Principled BSDF.
- Makes principled shader variations using constants. Removing a lot of duplicated code. This needed `const` keyword detection in `gpu_material_library.c`.
- SSR/SSS masking and data loading is a bit more consistent and defined outside of closure eval. The loading functions will act as accumulator if the lighting is not to be separated.
- SSR pass now do a full deferred lighting evaluation, including lights, in order to avoid interference with the closure eval code. However, it seems that the cost of having a global SSR toggle uniform is making the surface shader more expensive (which is already the case, by the way).
- Principle fully black specular tint now returns black instead of white.
- This fixed some artifact issue on my AMD computer on normal surfaces (which might have been some uninitialized variables).
- This touched the Ambient Occlusion because it needs to be evaluated for each closure. But to avoid the cost of this, we use another approach to just pass the result of the occlusion on interpolated normals and modify it using the bent normal for each Closure. This tends to reduce shadowing. I'm still looking into improving this but this is out of the scope of this patch.
- Performance might be a bit worse with this patch since it is more oriented towards code modularity. But not by a lot.

Render tests needs to be updated after this.

Reviewed By: jbakker
Differential Revision: https://developer.blender.org/D10390

# Conflicts:
#	source/blender/draw/engines/eevee/eevee_shaders.c
#	source/blender/draw/engines/eevee/shaders/common_utiltex_lib.glsl
#	source/blender/draw/intern/shaders/common_math_lib.glsl
2021-02-13 18:43:09 +01:00
Campbell Barton
69e9e45744 Cleanup: macro hygiene, use parenthesis around operators 2021-02-13 17:40:10 +11:00
Clément Foucault
000a340afa EEVEE: Depth of field: New implementation
This is a complete refactor over the old system. The goal was to increase quality
first and then have something more flexible and optimised.

|{F9603145} | {F9603142}|{F9603147}|

This fixes issues we had with the old system which were:
- Too much overdraw (low performance).
- Not enough precision in render targets (hugly color banding/drifting).
- Poor resolution near in-focus regions.
- Wrong support of orthographic views.
- Missing alpha support in viewport.
- Missing bokeh shape inversion on foreground field.
- Issues on some GPUs. (see T72489) (But I'm sure this one will have other issues as well heh...)
- Fix T81092

I chose Unreal's Diaphragm DOF as a reference / goal implementation.
It is well described in the presentation "A Life of a Bokeh" by Guillaume Abadie.
You can check about it here https://epicgames.ent.box.com/s/s86j70iamxvsuu6j35pilypficznec04

Along side the main implementation we provide a way to increase the quality by jittering the
camera position for each sample (the ones specified under the Sampling tab).

The jittering is dividing the actual post processing dof radius so that it fills the undersampling.
The user can still add more overblur to have a noiseless image, but reducing bokeh shape sharpness.

Effect of overblur (left without, right with):
| {F9603122} | {F9603123}|

The actual implementation differs a bit:
- Foreground gather implementation uses the same "ring binning" accumulator as background
  but uses a custom occlusion method. This gives the problem of inflating the foreground elements
  when they are over background or in-focus regions.
  This is was a hard decision but this was preferable to the other method that was giving poor
  opacity masks for foreground and had other more noticeable issues. Do note it is possible
  to improve this part in the future if a better alternative is found.
- Use occlusion texture for foreground. Presentation says it wasn't really needed for them.
- The TAA stabilisation pass is replace by a simple neighborhood clamping at the reduce copy
  stage for simplicity.
- We don't do a brute-force in-focus separate gather pass. Instead we just do the brute force
  pass during resolve. Using the separate pass could be a future optimization if needed but
  might give less precise results.
- We don't use compute shaders at all so shader branching might not be optimal. But performance
  is still way better than our previous implementation.
- We mainly rely on density change to fix all undersampling issues even for foreground (which
  is something the reference implementation is not doing strangely).

Remaining issues (not considered blocking for me):
- Slight defocus stability: Due to slight defocus bruteforce gather using the bare scene color,
  highlights are dilated and make convergence quite slow or imposible when using jittered DOF
  (or gives )
- ~~Slight defocus inflating: There seems to be a 1px inflation discontinuity of the slight focus
  convolution compared to the half resolution. This is not really noticeable if using jittered
  camera.~~ Fixed
- Foreground occlusion approximation is a bit glitchy and gives incorrect result if the
  a defocus foreground element overlaps a farther foreground element. Note that this is easily
  mitigated using the jittered camera position.
|{F9603114}|{F9603115}|{F9603116}|
- Foreground is inflating,  not revealing background. However this avoids some other bugs too
  as discussed previously. Also mitigated with jittered camera position.
|{F9603130}|{F9603129}|
- Sensor vertical fit is still broken (does not match cycles).
- Scattred bokeh shapes can be a bit strange at polygon vertices. This is due to the distance field
  stored in the Bokeh LUT which is not rounded at the edges. This is barely noticeable if the
  shape does not rotate.
- ~~Sampling pattern of the jittered camera position is suboptimal. Could try something like hammersley
  or poisson disc distribution.~~Used hexaweb sampling pattern which is not random but has better
stability and overall coverage.
- Very large bokeh (> 300 px) can exhibit undersampling artifact in gather pass and quite a bit of
  bleeding. But at this size it is preferable to use jittered camera position.

Codewise the changes are pretty much self contained and each pass are well documented.
However the whole pipeline is quite complex to understand from bird's-eye view.

Notes:
- There is the possibility of using arbitrary bokeh texture with this implementation.
  However implementation is a bit involved.
- Gathering max sample count is hardcoded to avoid to deal with shader variations. The actual
  max sample count is already quite high but samples are not evenly distributed due to the
  ring binning method.
- While this implementation does not need 32bit/channel textures to render correctly it does use
  many other textures so actual VRAM usage is higher than previous method for viewport but less
  for render. Textures are reused to avoid many allocations.
- Bokeh LUT computation is fast and done for each redraw because it can be animated. Also the
  texture can be shared with other viewport with different camera settings.
2021-02-12 22:35:52 +01:00