Billboard transparency

[thepenguinking]

This may sound weird, but Game Maker is using a dll made from irrlicht, which is amazing. Unfortunaly, no one on the game maker forum knows how to use irrlicht therefore dont know the basics for this dll. Thats why im askin here....kinda odd. I was wondering, with billboards, how do you make a certain colour unseen or fully transparent without affecting the rest of the image?

[Domarius]

Generally speaking, you make a TIFF or TGA image with an alpha channel. When you load the image, the alpha channel will be applied (black areas are transparent, white areas are opaque). That's the typical way to do it with 3D games. I say 'generally speaking' since I'm new to Irrlicht and don't know if there are any differences with the way you do it.

I know the way they do it in the Irrlict TechDemo, is without using alpha channels, and set 'additive' blending mode on the Billboard (can't remember the exact syntax).
Adding the colour values causes black to not show up, but you get a glowing effect that isn't the same as an alpha channel, more for glowing things, like fireballs, or fire particles or something.

[Guest]

I guess you could also set the material color for the alpha channel. I haven't tested it but it should work.