Broomstick: BitmapMaterial transparency

[0L4F]

Hello all,

I've set up an Away3D - Flash IDE project. I'm using Sprites from the
Flash library to create BitmapMaterials for Planes in Away3D.

I'd really like the Sprite's transparencies (alpha channel) to show up
in the BitmapMaterials, but I can't seem to get it to work :(

Here's my code:

textSprite = new TextSprite(); // Sprite
object from the Flash libraty
matSprite = new BitmapMaterial(getBitmapData(textSprite));

//matSprite.transparent = true; // doesn't do the trick

matSprite.lights = [light1];

matSprite.diffuseMethod = new BasicDiffuseMethod();
matSprite.diffuseMethod.alphaThreshold = 0.5; // no
luck!


private function
getBitmapData(srcSprite:Sprite):BitmapData
{
var bmd:BitmapData = new BitmapData(srcSprite.width,
srcSprite.height);
var b:Bitmap = new Bitmap(bmd);
bmd.draw(srcSprite);
return(bmd);
}

I'd appreciate any hints / pointers! Thanks in advance,

0L4F

[Fabrice3D]

oops I see the method is beneath...
try change var bmd:BitmapData = new BitmapData(srcSprite.width, srcSprite.height);
by something like var bmd:BitmapData = new BitmapData(srcSprite.width, srcSprite.height, true, 0xFFFFFFFF);

and var b:Bitmap = new Bitmap(bmd); what is it for?

Fabrice

[Fabrice3D]

getBitmapData...
what is this method doing exactly?

Fabrice

On Jul 25, 2011, at 2:31 PM, 0L4F wrote:

[0L4F]

Fabrice, you rock!

var bmd:BitmapData = new BitmapData(srcSprite.width, srcSprite.height,

true, 0x00000000);

combined with

matSprite.transparent = true;

did the trick.


Thanks :)

[0L4F]

Ah, just a very simple method that receives a Sprite Object, and
returns the corresponding BitmapData.

var b:Bitmap = new Bitmap(bmd); is redundant code, whoops ;)

cheers,

0L4F

[wagster]

I'm still struggling with this one... here's my class


public class Floor extends Plane
{
public function Floor(floorMc:MovieClip, segmentsW:uint=1,
segmentsH:uint=1, yUp:Boolean=true)
{
var bitmapData:BitmapData = new BitmapData(2048, 2048, true,
0x00000000);
bitmapData.draw(floorMc);
var floorMaterial:BitmapMaterial = new BitmapMaterial(bitmapData,
false);
super(floorMaterial, floorMc.width, floorMc.height, 1, 1, true);
rotationX = 90;
trace();
}
}

Firstly, I would like to create a BitmapData object the same size as
the MovieClip, but Texture3DProxy throws a "size must be power of 2"
error unless I set both height and width to a power of two, so

new BitmapData(floorMc.width, floorMc.height, true, 0x00000000)

doesn't work.

Secondly, I can't set the BitmapMaterial to transparent = true as
suggested above - because BitmapMaterial doesn't have a transparent
property.

I'm trying to do much the same thing - draw a Sprite onto a plane and
show only the opaque parts of the Sprite.

Any ideas?

Cheers,

Wag

[richardolsson]

The properties for transparency are alphaBlending and alphaThreshold.
See a short explanation of them here:
http://groups.google.com/group/away3d-dev/browse_thread/thread/c62a6f8d8409b703/2c53be3228c4295a?show_docid=2c53be3228c4295a

Cheers
/R