Page MenuHome
Create Task
Maniphest T42356

Changing vertex color alpha has no effect on transparency when using GLSL shading
Closed, ArchivedPublic
Actions

Description

System Information
Windows 7 64-bit
Intel HD Graphics 4000

Blender Version
Broken: 2.71 9337574, 2.72 9e963ae

Files

VertexAlpha.blend527 KBDownload
- Contains a plane that runs a script changing its vertex color and alpha values when the game engine is started

Description
Start the game engine in the attached file and notice that while the vertex colors are changed, their alpha values are not (note that the actual alpha values of the vertices are changed and can be verified by calling print(vert.a), but changing the alpha value has no visual effect on the plane's transparency). If you change the shading mode from GLSL to Multitexture, you'll see that the transparency is now correctly changed.

Related Objects

Event Timeline

mobious created this task.Oct 22 2014, 11:58 PM
mobious raised the priority of this task from to 90.
mobious updated the task description. (Show Details)
mobious added a project: Game Engine.
mobious edited a custom field.
mobious added a subscriber: mobious.
mobious added a comment.Oct 23 2014, 12:33 AM

Something else I noticed:
If you change the viewport shading to Solid instead of Textured/Material, the transparency is changed correctly when in GLSL. This has the opposite effect in Multitexture mode, e.i. the plane's transparency is not changed when using Solid viewport shading in Multitexture mode.

Mike Erwin (merwin) added a subscriber: Mike Erwin (merwin).Feb 1 2015, 4:41 PM
Thomas Szepe (hg1) added a subscriber: Thomas Szepe (hg1).Apr 26 2015, 11:27 PM

Vertex transparency was never implemented in GLSL.
Vertex transparency actual only works in multitexture mode (OpenGL fixed function pipeline). If you change the viewport shading in GLSL to Solid it will also renders in shadeless multitexture mode. That is the reason why it works in GLSL to Solid.

For GLSL you only can use different materials for each color. But material color and alpha are also not changeable at the moment. You can use this only if you don't want change it.
The only possibility for the moment if you want to change multiple alpha values or colors for an object, is to split the mesh into more objects, parent it together and change the object color and/or alpha of it.

Angus Hollands (agoose77) added a subscriber: Angus Hollands (agoose77).May 15 2015, 5:02 PM

Can this be closed?

Jorge Bernal (lordloki) changed the task status from Unknown Status to Unknown Status.May 16 2015, 1:57 AM
Jorge Bernal (lordloki) claimed this task.

This is a feature request. I moved it to our Game Engine TODO list: http://wiki.blender.org/index.php/Dev:2.5/Source/Development/Todo/GameEngine

Closing the report. Thanks for your time.