seems simple enough. SO by 2d object, im assuming you mean a sprite, or do you want a plane or somthing...
If its a sprite, i can help, but i stink at 3d, so ill stear clear of that...
If its a sprite, you want to change its alpha value. you can do that with an amazing command called, set sprite diffuse...
This next part is copied RIGHT out of the help files
This command will set the alpha value of the specified sprite. The alpha controls how much of the sprite is
present on screen and is used to create a translucent sprite. The Alpha value range is 0 to 255, with 255
being completely solid and 0 being invisible. The parameters should be specified using integer values.
Syntax
SET SPRITE ALPHA Sprite Number, Alpha Value
so, to use it, run somthing like this code.. ( im making this on the fly, but i think it should work)
box 0,0,100,20 ` This is a box that could be a health bar
get image 1,0,0,100,20,1`Were just coonverting that box into an `image
CLS
sprite 1,0,0,1 `Making the sprite that is the bar
set sprite diffuse 1,120`Now were using the command to make is `visable... Its visibilty is 120/255, so its pretty see through
`Now we just need to prove that it is see through...
text 0,10,"A See through bar!!! ZOMG!!! CRAZY l337 HAXXOR!!!! LOL!!! ROFL!!!!! POOP!!!!!!!!!!!!!!!"
suspend for key
Sorry for the wierdness of the text in that code by the way...
That should be what you need. Best of luck