Geez man, RTFM Ok, I’ll take a stab at this-
Blending modes (Add, Sub, Mult, etc) - These planes were vertex painted with Red, Green, and Blue circles (in that order) with the various blending modes.
Add - The RGB values are ADDED together, so when you paint Red (RGB 1,0,0) and then Green (RGB 0,1,0) , you get Yellow (RGB 1,1,0)
Mix - The RGB values get OVERWRITTEN, so when you paint Red (RGB 1,0,0) and then Green (RGB 0,1,0) , the Green will overtake the red and eventually you will end up with just Green (RGB 0,1,0) Notice how the circles overlap instead of blend together.
Subtract - The RGB values get SUBTRACTED, so if you start off with White (RGB 1,1,1) and then paint Red (RGB 1,0,0), you’ll end up with that blinding shade of Blue we call Cyan (RGB 0,1,1) This blend mode is kinda like painting with watercolors.
Multiply - The RGB values get MULTIPLIED, so if you start off with White (RGB 1,1,1) and then paint Red (RGB 1,0,0), you’ll just end up with Red (RGB, 1, 0, 0) since the Red channel was multiplied by 1, and the Green and Blue channels were multiplied by zero.
Now say you painted Green (RGB 0,1,0) on top of this Red (1,0,0), you’ll actually end up with Black (0,0,0) since the Red channel (the only one remaining at this point) gets multiplied by zero.
Fliter - This one’s kind of the oddball… not very useful and better left untouched
About the Face Buttons,
Opaque - Makes your faces opaque (non-transparent). The vast majority of your polygons will be set like this since most of our environment isn’t transparent :).
Add - Just like the blending mode for vertex paint, Add mode adds the color of the polygon to whatever’s behind it. Used anywhere you need a brightening effect, like fire, explosions or neon lights.
Alpha - Makes the polygon transparent. The transparency will depend on your texture’s alpha channel (look in your image editor’s help for information on how to make one) or the polygon’s material. This mode is commonly used for smoke and water.
Light - Shades the polygon based on the lights in your scene. It will only respond to lights on the same layer and only up to a maximum of 8 lights. This is used whenever your object will be moving, like for your characters and props. Don’t use it for your environment however- vertex painting is generally better for that.
Shadow - Puts the polygon flat on the floor to simulate a shadow. Say you were making a Mario type game- you’d add a black circle (and move the points upward slightly because you’ll want to seperate it from the ground) and parent it to your character model. Set the faces on the circle to shadow, and now whenever your character jumps, the shadow will stay behind on the ground.
Best way to really understand all of this is to experiment. Good luck!