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Glow effect

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for fullscreen glow (or bloom), you usually do it as a post-processing effect using render to texture, bright-pass and then gaussian blur.

if you only need it on a pr light-basis, you can simply draw a billboard-flare at the position of the light.

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hey,

yeah, you can see a billboard intersection with the engine. Methinks it's a couple of static textured quads set, then turning off depth testing and setting the blend mode to add and then drawing a glow billboard. But that's just me, from my GL background...

--CJM

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I agree that it is definately a couple textured quads, but it also seems as though there is a bit of bloom in it. Obviously not a fully dynamic star bloom, but based on the small amount of spill-over that seems to be there that follows the contour or the engine, I would say that what has been done is that is was made with a series of quads, and then a simple bloom post-effect was applied.

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Quote:
Original post by tokaplan
Anyone please tell me in short what "post-processing" effect is, I'm not quite following ((

A "post-processing effect" is when you perform some type of image algorithm on a texture. Most times, you will render geometry to a render-target. You will then render that render-target as a textured-quad. At that point, the post-processing effect is performed in the vertex and pixel shaders.

There are many common PP algorithms, like blur (there are tons of these), bloom, and many imaging ones (like converting to grayscale, edge finder, ect...). Check out the SDK sample to see exactly how they work.

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Quote:
Original post by circlesoft
There are many common PP algorithms, like blur (there are tons of these), bloom, and many imaging ones (like converting to grayscale, edge finder, ect...).

There are also lots of uncommon ones, limited only by what you can use/abuse shaders for [grin]. Post processing effects with pixel shaders are great fun if nothing else...

Quote:
Original post by circlesoft
Check out the SDK sample to see exactly how they work.

My personal favourite, and top recommendation, is the PostProcess C++/D3D9 sample. Although that obviously requires you to be working with D3D9 and C++ [smile]. The accompanying article with that sample is worth reading even if you're not able to use that particular sample.

hth
Jack

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Quote:
Original post by jollyjeffers
My personal favourite, and top recommendation, is the PostProcess C++/D3D9 sample. Although that obviously requires you to be working with D3D9 and C++ [smile]. The accompanying article with that sample is worth reading even if you're not able to use that particular sample.

Yea that was the one I was talking about. Actually, the Nvidia SDK is the probably the best resource for post-processing shaders - there are tons of them included (as well as many other types of shaders).

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Quote:
Original post by tokaplan
Does it mean that applying any pixel shader is always post-processing?

No, post-processing is a special case of using a pixel shader.

The key difference is that post-processing is done (as the name suggests) AFTER the main rendering - thus you're almost always operating on a 2D input and a 2D output... you're not actually applying the pixel shaders to the materials that make up the individual triangles of the model(s) you've rendered.

hth
Jack

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Postprocessing is simply performing some processing on your frame buffer after everything had been rendered. Hence the name "Post" "Processing". (So the processing occurs is image space).

With modern gfx. cards this is usually done by rendering the scene into a texture (or to the frame buffer and copy it to a texture - to get anti-aliasing) and then rendering that texture to the screen using a full-screen 2D quad that uses a pixelshader that reads in the incoming pixels from the scene texture, applies some calculation to them and then outputs them to the frame buffer for display.

Just using a pixel-shader is not post processing. Using a pixel-shader in the way I have just described is an example or post processing.

Both ATI and nVidia have some good slides\papers on this topic so it's worth checking out their sites.

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