I'd like to use Blender 2.93.5 for modelling vertex coloured meshes but I'm unable to see the effects of Erase Alpha in vertex paint mode. I can see the alpha transparency in Blender 2.79c (nightly build) but not in 2.93.5.
Note: The meshes are to be used in a game engine with no textures or normals etc. The only attribute the vertices will have is an RGBA colour.
In Blender 2.79c you can see the effects of Alpha transparency using the Erase Alpha brush mode on the bottom vertices:
An exported 2.79c .ply file shows the vertices with the alpha set to zero, (the rightmost value, the 'A' of the RGBA value):
Note that in 2.79c I'm using the default material and have done nothing more than start Blender, added the plane mesh and then applied the vertex paint and erase alpha. The Renderer is set to Blender Render as per default.
Trying to reproduce this in 2.93.5 doesn't work. Here's another blueish painted plane with the bottom two vertices with Erase Alpha applied. I have tried Workbench, Cycles and EEVEE as the renderers:
An exported 2.93.5 .ply file shows the vertices with the alpha set to zero:
I've set up a nodes 2.93.5 shader like this hoping it would work:
I feel like I'm missing something obvious. In this link it mentions in the tip 'In order to see the effects of the Erase and Add Alpha mix modes in the Image Editor, you must enable the alpha channel display by clicking the Display Alpha or the Alpha-Only button. Transparent (no alpha) areas will then show a checkered background.', but I cannot find these buttons anywhere.
Any help would be appreciated :-)