EEVEE: Add support for extracting alpha channels from a color #72941
Labels
No Label
Interest
Alembic
Interest
Animation & Rigging
Interest
Asset Browser
Interest
Asset Browser Project Overview
Interest
Audio
Interest
Automated Testing
Interest
Blender Asset Bundle
Interest
BlendFile
Interest
Collada
Interest
Compatibility
Interest
Compositing
Interest
Core
Interest
Cycles
Interest
Dependency Graph
Interest
Development Management
Interest
EEVEE
Interest
EEVEE & Viewport
Interest
Freestyle
Interest
Geometry Nodes
Interest
Grease Pencil
Interest
ID Management
Interest
Images & Movies
Interest
Import Export
Interest
Line Art
Interest
Masking
Interest
Metal
Interest
Modeling
Interest
Modifiers
Interest
Motion Tracking
Interest
Nodes & Physics
Interest
OpenGL
Interest
Overlay
Interest
Overrides
Interest
Performance
Interest
Physics
Interest
Pipeline, Assets & IO
Interest
Platforms, Builds & Tests
Interest
Python API
Interest
Render & Cycles
Interest
Render Pipeline
Interest
Sculpt, Paint & Texture
Interest
Text Editor
Interest
Translations
Interest
Triaging
Interest
Undo
Interest
USD
Interest
User Interface
Interest
UV Editing
Interest
VFX & Video
Interest
Video Sequencer
Interest
Virtual Reality
Interest
Vulkan
Interest
Wayland
Interest
Workbench
Interest: X11
Legacy
Blender 2.8 Project
Legacy
Milestone 1: Basic, Local Asset Browser
Legacy
OpenGL Error
Meta
Good First Issue
Meta
Papercut
Meta
Retrospective
Meta
Security
Module
Animation & Rigging
Module
Core
Module
Development Management
Module
EEVEE & Viewport
Module
Grease Pencil
Module
Modeling
Module
Nodes & Physics
Module
Pipeline, Assets & IO
Module
Platforms, Builds & Tests
Module
Python API
Module
Render & Cycles
Module
Sculpt, Paint & Texture
Module
Triaging
Module
User Interface
Module
VFX & Video
Platform
FreeBSD
Platform
Linux
Platform
macOS
Platform
Windows
Priority
High
Priority
Low
Priority
Normal
Priority
Unbreak Now!
Status
Archived
Status
Confirmed
Status
Duplicate
Status
Needs Info from Developers
Status
Needs Information from User
Status
Needs Triage
Status
Resolved
Type
Bug
Type
Design
Type
Known Issue
Type
Patch
Type
Report
Type
To Do
No Milestone
No project
No Assignees
3 Participants
Notifications
Due Date
No due date set.
Dependencies
No dependencies set.
Reference: blender/blender#72941
Loading…
Reference in New Issue
No description provided.
Delete Branch "%!s(<nil>)"
Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?
I mistakenly filed a bug report --> #72856 EEVEE transparency problem with mtpaint PNG
I didn't fully understand the bug and attached a blender file that didn't show the bug properly.
Packing the image file with blender command 'Pack' makes the image
opaque so it is worthless to include a blender document. I will
include a mtpaint PNG image instead and you can load it into
blender 2.81 yourself and see how it renders in EEVEE versus cycles.
I noticed that your forum converts the image to opaque if I try to attach to this post
so I'll use a shareable link that preserves the transparency:
https://drive.google.com/open?id=1TjfSjzabYEmVHXTODPFymGVNwuL02SnJ
Here is how I created the mtpaint image to reproduce the problem...
EEVEE rendering doesn't respect the transparent region.
Cycles rendering does respect the transparent region.
Not a high priorty.
Added subscriber: @don570
mtpaint transparency problem in EEVEE renderto EEVEE: Add support for extracting alpha channels from a colorAdded subscriber: @Jeroen-Bakker
Changed status from 'Needs Triage' to: 'Confirmed'
Hi @don570
I have to file this as a To Do. EEVEE currently does not support alpha extraction from a color. This can be added, but that is adding a new feature, and not a bug.
I see two ways how to implement this.
I expect that the shader compilation would be preferred (performance & memory).
Added subscriber: @Foaly
I disagree, this is a bug.
The problem is rather that ImBuf does not correctly read the tRNS chunk for RGB images (although it already does for grayscale and palette images).
Solving this should be as easy as adding another
png_set_expand
call.It has nothing to do with EEVEE, the same problem occurs in all other areas of Blender.
It's just a coincidence that Cycles implemented its image loading separately.
As for implementing this with a separate shader:
Please don't: It's not worth the time and added complexity, considering that such files are rare.
The developer of mtpaint (wjaguar) https://github.com/wjaguar/mtPaint
contacted me, and here is what he wrote...
Hey guys, I don't disagree that it is an issue. According to the rules of the bug-tracker we decided upon the next rules https://code.blender.org/2019/12/tracker-curfew/
code was not intended to work as expected by the reporters. Issue is in ImBuf what needs a large overhaul as it has many issues. We can hack something, but that would lead to more maintenance. Doing it once good will reduce maintenance, but will need a new design. Hence I filed it as a todo.