Blender questions from the 2.x manual and gamekit vol1.sec2

Ok here is the second installment in the things I did not understand from the blender manual and the gamekit book.

In the explanation of the face buttons the manual and the game kit says about the Add button.

"Add:
Faces are rendered transparent. The color of the face is added to what has already been drawn. Black areas in the texture are transparent, white are fully brite. Use this option to achieve light beam effects,glows or halos around lights. For real transparency ust the next option “Alpha” "

Ok I understand most of this. But WHAT color. The material color of the mesh? The vertex paint color you are applying with the brush? What.?

the color of the stuff behind the face that has already been drawn

textures, vertex colors, lighting, everything

it is exactly like add mode in photoshop

[/quote]the color of the stuff behind the face that has already been drawn

textures, vertex colors, lighting, everything

it is exactly like add mode in photoshop

Do you mean the “stuff” in the same object? or another object that might be behind the one you are working on from the perspective of the 3d window?

anything that has already been drawn

so, when the game engine is running that is everything opaque behind the current object and any add or alpha mode faces that have already been drawn

however, the 3d view acts different [because opaque faces aren’t always drawn first, and every face writes to the zbuffer, so a tranparent add mode face can obscure opaque faces if drawn first and is closer to the camera]