SpriteBatch does in fact use VertexPositionColorTexture vertices internally, so you'd assume it could easily support 3d sprites. But no. They don't expose any draw methods that take 3d coordinates, and they have an intermediate internal data format that doesn't support 3d coordinates.
If they wanted to support it, they certainly could, and you can ask for it. But if you are capable of understanding 3d concepts enough to NEED 3d sprites, then you are capable of just writing your own. It should take you about 5 minutes to write your own SpriteBatch. Couple more minutes to make it use Indexed drawing.
Can we render sprites with 3d world coordinates?
Nordsee
Mike L Hayes
Sure it does, all you need is a sprite class (rendering quads) in 3D space.
The only real difference between 2D and 3D is that you can set depth on the object, and rotate it around the third axis.
nira
If they wanted to support it, they certainly could, and you can ask for it. But if you are capable of understanding 3d concepts enough to NEED 3d sprites, then you are capable of just writing your own. It should take you about 5 minutes to write your own SpriteBatch. Couple more minutes to make it use Indexed drawing.