Multitexturing and alpha

BlitzMax Forums/MiniB3D Module/Multitexturing and alpha

Ion	(Posted 2011) [#1]

Hi, I have a couple of textures (size 8x8 pixels) which I want to blend over each other. Each texture is a part of a character, for instance I have one texture for the head, one for the body and so forth.
The textures contain large areas of transparent areas (more than half of the head texture is alpha etc.)

I use this code below to render the textures to a cube (for debugging):

Import sidesign.minib3d
Strict

Graphics3D 640,480

Local camera:TCamera=CreateCamera()
MoveEntity camera,0,0,-3
AmbientLight 255,255,255

Local cube:TMesh=CreateCube()
Local tex1:TTexture=LoadTexture("media/pic1.png", 2)
Local tex2:TTexture=LoadTexture("media/pic2.png", 2)
TextureBlend tex1,1
TextureBlend tex2,1

EntityTexture cube,tex1,0,0
EntityTexture cube,tex2,0,1

CameraClsColor(camera, 0, 0, 255)
While Not KeyDown(KEY_ESCAPE)
	If AppTerminate() End
	TurnEntity(cube, 0, 0.1, 0)
	RenderWorld
	Flip
Wend

Without the fix presented here: http://blitzbasic.com/Community/posts.php?topic=94623 this does not work at all, just leaving a black cube.
Using the fix, the textures blend fine, but all transparent areas now become white. Any one got a hint here?

EDIT: Media:

Last edited 2011

jkrankie

(Posted 2011) [#2]

I'm probably wrong, but you might need to make sure the entity is using alpha blending, i think that's entityFX 32.

Cheers
Charlie

Ion	(Posted 2011) [#3]

Naw that didn't do anything. Thanks for the suggestion though.

AdamRedwoods

(Posted 2011) [#4]

Your base color may be white.

If you need a texture as the base, set the TextureBlend(0)
Then with the fix (GL_DECAL), TextureBlend(1) for textures on top layers.

The problem with gl_decal, is it isn't affected by opengl lights.