Lens Flare
Reading the depth buffer is a very slow operation, especially on cards that haven''t got an explicit Z-buffer (the Kyro range of chipset, for instance). The better way to solve this problem is to use your collision detection routines to cast a ray from the camera to the sun and see whether it hits anything. Writing collision detection just for this is a bit overkill, but I think you''d need it anyway.
Hi..
Like Kippesoep said.. I would really recommend using a ray to detect a possible collision..
There are some very good tutorials at this site: http://www.gametutorials.com/Tutorials/OpenGL/OpenGL_Pg3.htm
You are going to need collision detection at some point.. whether you are writing a demo or a game..
Cya
Halloko
Like Kippesoep said.. I would really recommend using a ray to detect a possible collision..
There are some very good tutorials at this site: http://www.gametutorials.com/Tutorials/OpenGL/OpenGL_Pg3.htm
You are going to need collision detection at some point.. whether you are writing a demo or a game..
Cya
Halloko
Reading the depth-buffer back to memory is a big no-no; it''ll bring your poly through-put to it''s knees.
If you''re not too worried about your Collision Detection, represent the geometry as OOBBs, or AABBs. Test the collision with a simple ray-cast.
One trick to make lens-flares, and halos, (not just from suns, but from other lightsource) look cool is to slowly fade it in (alpha 0 -> 1 upon first viewable) and out as it comes into and out of view.
Allan
If you''re not too worried about your Collision Detection, represent the geometry as OOBBs, or AABBs. Test the collision with a simple ray-cast.
One trick to make lens-flares, and halos, (not just from suns, but from other lightsource) look cool is to slowly fade it in (alpha 0 -> 1 upon first viewable) and out as it comes into and out of view.
Allan
reading back buffer is the slowest but also the simplest solution. you can minimize stall by doing it as the last thing before buffer swap but it will still caouse a bubble in gl pipeline. you can get some (%5) decrease even on slow cards like TNT while this can be bigger on new ones, specialy when using VAR
You should never let your fears become the boundaries of your dreams.
You should never let your fears become the boundaries of your dreams.
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