Generell kann man Transparenz in OpenGL durch Blending erreichen d.h. Pixel, die beim Rendern übereinander in den Framebuffer gezeichnet werden, werden miteinander verrechnet um die letztliche Farbe für dieses Pixel zu bestimmen. Eingeschaltet wird die Blending-Funktionalität via glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA) und  [ Read More ]

Complex calculations often require more than one single rendering process. Therefore the rendering pipeline is passed multiple times. This is usually done in a serial order, where every render pass works on specific input data. Filter- and post processing operations  [ Read More ]

Offscreen Rendering represents a rendering process which ignores the standard visible frame buffer and stores rendered data in an alternative buffer not being displayed after rendering. This buffer is called the render target. The case of using a texture as  [ Read More ]

Some graphical operations require computations to be done on every pixel on the image plane. Any post processing steps and image filter operations in particular are typical examples. Therefor a rendering step is necessary that does not consider specific geometry  [ Read More ]