0
votes
1answer
150 views

Transparency in opengl - texture with alpha, color from background [duplicate]

I have to draw texture with transparent areas on square. But I don't want this transparencies to take color from this polygon, but from the background. Do you have any good tutorial to achieve it? ...
0
votes
1answer
101 views

Correct GL settings to mix 2D and 3D rendering

I'm programming a 3D game engine with 2D GUI. The GUI objects have partially transparent textures and the transparency works more or less. The sky color is rendered in transparent areas of the ...
0
votes
3answers
328 views

OpenGL - How to draw a transition of two textures on one quad?

I know when drawing a rectangle, if we select red and draw two vertices, and then select yellow and draw the other two vertices, the entire rectangle will show a nice transition of color between those ...
9
votes
2answers
1k views

Why are some games using some dithering pattern instead of traditional alpha for transparency?

Recently, I have seen some 3D games (eg: GTA IV) to use some kind of ordered dithering to simulate transparency / alpha. The polygons are not transparent as usual, but instead render a dithering ...
1
vote
2answers
3k views

Transparent parts of texture are opaque black instead

I render a sprite twice, one on top of the other. The sprites have transparent parts, so I should be able to see the bottom sprite under the top sprite. The transparent parts are black (the clear ...
0
votes
1answer
238 views

Rendering two textures with blending and alpha test

What I am looking for is the following: I have a circle on a square image, alpha is 0 at the corners and also a square shadow, alpha is 0 everywhere else I would like to have as final result a ...
0
votes
1answer
961 views

Making a surface transparent from blackness of texture

I am making a "halo" shader in unity using GLSL. And I've come to a roadblock. What I need to do is take a texture, like the following, and make it transparent according to the darkness of it. And I ...
3
votes
1answer
2k views

Why do my sprites have a dark shadow/line/frame surrounding the texture?

I'm starting OpenGL with Apple's GLKit hand I'm having some trouble to get my sprites displayed properly. The Problem is that they all are surrounded with thin dark lines. The screen shot below shows ...
-1
votes
1answer
205 views

Selective jogl texture transparancy depending on bitwise magic?

I have rewritten some code to allow to load bitmaps to be loaded as textures and if a pixel has a max green color component it is marked transparent. What is odd is that I cannot use the value from a ...
5
votes
1answer
408 views

Line at edge of transparent texture on XNA mesh

I have a mesh that is computer generated with a texture on top of it with transparancy on one side. The SamplerState is set to LinearWrap because I would like the texture to wrap. The problem I have ...
6
votes
1answer
7k views

How to render a texture partly transparent?

Good Morning StackOverflow, I'm having a bit of a problem right now as I can't seem to find a way to render part of a texture transparently with openGL. Here is my setting : I have a quad, ...