"Surely the z-order issue is the same whether you use vertexalpha or "hardwired" animated alpha?"
Nope!
Entites which have alpha channels, or which use entity alpha are rendered in a second pass after the solide parts of a scene are rendered. During this pass, Z writes are disabled, but Z checking is enabled.
However, when Mark implemented vertex alpha, for some reason he neglected to have the entities that use the vertex alpha EntityFX flag check the zbuffer as they are being written.
So as it currently stands, vertex alpha is all but useless. Useful for a few limited effects, but not for widespread use.
Space_Guy:
Another movie with good particle effects is "The Road to El Dorado". They show in the extras how they used a realtively few simple 2D particles with animated textures to create highly realistic effects like a fountain with water that splashes and spreads out along the ground.
It's also a really good movie too. :-)
Nope!
Entites which have alpha channels, or which use entity alpha are rendered in a second pass after the solide parts of a scene are rendered. During this pass, Z writes are disabled, but Z checking is enabled.
However, when Mark implemented vertex alpha, for some reason he neglected to have the entities that use the vertex alpha EntityFX flag check the zbuffer as they are being written.
So as it currently stands, vertex alpha is all but useless. Useful for a few limited effects, but not for widespread use.
Space_Guy:
Another movie with good particle effects is "The Road to El Dorado". They show in the extras how they used a realtively few simple 2D particles with animated textures to create highly realistic effects like a fountain with water that splashes and spreads out along the ground.
It's also a really good movie too. :-)