Blender: overlay_antialiasing.cc File Reference

Blender V4.3

#include "DRW_render.hh"
#include "ED_screen.hh"
#include "overlay_private.hh"

Go to the source code of this file.

Functions
void	OVERLAY_antialiasing_init (OVERLAY_Data *vedata)

void	OVERLAY_antialiasing_cache_init (OVERLAY_Data *vedata)

void	OVERLAY_antialiasing_cache_finish (OVERLAY_Data *vedata)

void	OVERLAY_antialiasing_start (OVERLAY_Data *vedata)

void	OVERLAY_xray_depth_copy (OVERLAY_Data *vedata)

void	OVERLAY_xray_depth_infront_copy (OVERLAY_Data *vedata)

void	OVERLAY_xray_fade_draw (OVERLAY_Data *vedata)

void	OVERLAY_antialiasing_end (OVERLAY_Data *vedata)

Detailed Description

Overlay antialiasing:

Most of the overlays are wires which causes a lot of flickering in motions due to aliasing problems.

Our goal is to have a technique that works with single sample per pixel to avoid extra cost of managing MSAA or additional texture buffers and jitters.

To solve this we use a simple and effective post-process AA. The technique goes like this:

During wireframe rendering, we output the line color, the line direction and the distance from the line for the pixel center.
Then, in a post process pass, for each pixels we gather all lines in a search area that could cover (even partially) the center pixel. We compute the coverage of each line and do a sorted alpha compositing of them.

This technique has one major shortcoming compared to MSAA:

It handles (initial) partial visibility poorly (because of single sample). This makes overlapping / crossing wires a bit too thin at their intersection. Wireframe meshes overlaid over solid meshes can have half of the edge missing due to z-fighting (this has workaround). Another manifestation of this, is flickering of really dense wireframe if using small line thickness (also has workaround).

The pros of this approach are many:

Works without geometry shader.
Can inflate line thickness.
Coverage is very close to perfect and can even be filtered (Blackman-Harris, gaussian).
Wires can "bleed" / overlap non-line objects since the filter is in screen-space.
Only uses one additional lightweight full-screen buffer (compared to MSAA/SMAA).
No convergence time (compared to TAA).

Definition in file overlay_antialiasing.cc.

Function Documentation

◆ OVERLAY_antialiasing_cache_finish()

void OVERLAY_antialiasing_cache_finish ( OVERLAY_Data * vedata )

◆ OVERLAY_antialiasing_cache_init()

void OVERLAY_antialiasing_cache_init ( OVERLAY_Data * vedata )

Definition at line 105 of file overlay_antialiasing.cc.

References OVERLAY_PrivateData::antialiasing, OVERLAY_PassList::antialiasing_ps, DRW_Global::block_ubo, DefaultTextureList::depth, DRW_PASS_CREATE, DRW_shgroup_call_procedural_triangles(), DRW_shgroup_create(), DRW_shgroup_uniform_block, DRW_shgroup_uniform_bool_copy(), DRW_shgroup_uniform_float_copy(), DRW_shgroup_uniform_texture_ref(), DRW_STATE_BLEND_ALPHA_PREMUL, DRW_STATE_BLEND_MUL, DRW_STATE_WRITE_COLOR, DRW_viewport_texture_list_get(), OVERLAY_PrivateData::enabled, G_draw, OVERLAY_TextureList::overlay_color_tx, OVERLAY_TextureList::overlay_line_tx, OVERLAY_shader_antialiasing(), OVERLAY_shader_xray_fade(), OVERLAY_StorageList::pd, OVERLAY_Data::psl, OVERLAY_Data::stl, OVERLAY_TextureList::temp_depth_tx, OVERLAY_Data::txl, USER_GPU_FLAG_OVERLAY_SMOOTH_WIRE, OVERLAY_PrivateData::xray_enabled, OVERLAY_PassList::xray_fade_ps, and OVERLAY_PrivateData::xray_opacity.

Referenced by OVERLAY_cache_init().

◆ OVERLAY_antialiasing_end()

void OVERLAY_antialiasing_end ( OVERLAY_Data * vedata )

Definition at line 247 of file overlay_antialiasing.cc.

References OVERLAY_PrivateData::antialiasing, OVERLAY_PassList::antialiasing_ps, DRW_draw_pass(), DRW_viewport_framebuffer_list_get(), OVERLAY_PrivateData::enabled, GPU_framebuffer_bind(), DefaultFramebufferList::overlay_only_fb, OVERLAY_StorageList::pd, OVERLAY_Data::psl, and OVERLAY_Data::stl.

Referenced by OVERLAY_draw_scene().

◆ OVERLAY_antialiasing_init()

void OVERLAY_antialiasing_init ( OVERLAY_Data * vedata )

Definition at line 49 of file overlay_antialiasing.cc.

References OVERLAY_PrivateData::antialiasing, DRW_Global::block, DefaultTextureList::color_overlay, DRW_state_is_fbo(), DRW_TEX_FILTER, DRW_texture_create_2d(), DRW_texture_ensure_fullscreen_2d(), DRW_viewport_texture_list_get(), OVERLAY_TextureList::dummy_depth_tx, OVERLAY_PrivateData::enabled, OVERLAY_Data::fbl, G_draw, GPU_DEPTH_COMPONENT24, GPU_framebuffer_ensure_config, GPU_RGBA8, GPU_SRGB8_A8, OVERLAY_FramebufferList::overlay_color_only_fb, OVERLAY_TextureList::overlay_color_tx, OVERLAY_FramebufferList::overlay_default_fb, OVERLAY_FramebufferList::overlay_line_fb, OVERLAY_TextureList::overlay_line_tx, OVERLAY_StorageList::pd, GlobalsUboStorage::size_pixel, OVERLAY_Data::stl, OVERLAY_Data::txl, and USER_GPU_FLAG_OVERLAY_SMOOTH_WIRE.

Referenced by OVERLAY_engine_init().

◆ OVERLAY_antialiasing_start()

void OVERLAY_antialiasing_start ( OVERLAY_Data * vedata )

Definition at line 186 of file overlay_antialiasing.cc.

References OVERLAY_PrivateData::antialiasing, OVERLAY_PrivateData::clear_in_front, DRW_state_is_fbo(), OVERLAY_PrivateData::enabled, OVERLAY_Data::fbl, GPU_framebuffer_bind(), GPU_framebuffer_clear_color(), GPU_framebuffer_clear_depth(), OVERLAY_FramebufferList::overlay_in_front_fb, OVERLAY_FramebufferList::overlay_line_fb, OVERLAY_StorageList::pd, and OVERLAY_Data::stl.

Referenced by OVERLAY_draw_scene().

◆ OVERLAY_xray_depth_copy()

void OVERLAY_xray_depth_copy ( OVERLAY_Data * vedata )

Definition at line 205 of file overlay_antialiasing.cc.

References OVERLAY_PrivateData::antialiasing, DefaultTextureList::depth, OVERLAY_PrivateData::do_depth_copy, DRW_state_is_fbo(), DRW_viewport_texture_list_get(), OVERLAY_Data::fbl, GPU_framebuffer_bind(), GPU_framebuffer_clear_depth(), GPU_texture_copy(), OVERLAY_FramebufferList::overlay_default_fb, OVERLAY_StorageList::pd, OVERLAY_Data::stl, OVERLAY_TextureList::temp_depth_tx, OVERLAY_Data::txl, and OVERLAY_PrivateData::xray_enabled.

Referenced by OVERLAY_draw_scene().

◆ OVERLAY_xray_depth_infront_copy()

void OVERLAY_xray_depth_infront_copy ( OVERLAY_Data * vedata )

Definition at line 224 of file overlay_antialiasing.cc.

References OVERLAY_PrivateData::antialiasing, DefaultTextureList::depth_in_front, OVERLAY_PrivateData::do_depth_infront_copy, DRW_state_is_fbo(), DRW_viewport_texture_list_get(), GPU_texture_copy(), OVERLAY_StorageList::pd, OVERLAY_Data::stl, OVERLAY_TextureList::temp_depth_tx, and OVERLAY_Data::txl.

Referenced by OVERLAY_draw_scene().

◆ OVERLAY_xray_fade_draw()

void OVERLAY_xray_fade_draw ( OVERLAY_Data * vedata )

Definition at line 236 of file overlay_antialiasing.cc.

References DRW_draw_pass(), DRW_state_is_fbo(), OVERLAY_StorageList::pd, OVERLAY_Data::psl, OVERLAY_Data::stl, OVERLAY_PrivateData::xray_enabled, OVERLAY_PassList::xray_fade_ps, and OVERLAY_PrivateData::xray_opacity.

Referenced by OVERLAY_draw_scene().