Is there anyway I can copy what''s in the back buffer to a texture? I don''t want to render to a texture, because then I would need to render to the texture and then re-render to screen (or at least put the texture on screen with orthoview).

there is a way i think. look at ARB_render_texture or ARB_buffer_region, dunno which can help, but sure one of them will

Try glReadPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLvoid* pixels);

I''''m making my own coaster sim & theme park!!

it works but damned slow i think

How about using glCopyTexSubImage2D?

Nutty has an example to create dynamic cubemaps which renders to the backbuffer and then uses glCopyTexSubImage, perhaps it will help you.

http://opengl.nutty.org/extensions/index.html

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Amusing quote deleted at request of owner

Hmmm, it doesn't look like any of those will work because I need to maintain my viewport while rendering... let me give you an example of what I'm trying to do.

In Final Fantasy 10 there's this wonderful effect where there's a blur centered at a certain point. The way it looks like it's done is there is a screenshot of the last frame on a texture, then that's scretched about 10 pixels on either side to make it bigger than it was. Then its shifted over to be on top of the blur point, it makes for a very cool effect. It was like a radial zoom blur... but not, hard to explain.

I wish I could find a movie of it, but if you have Final Fantasy 10 I remember it when summoning Anima. If you have the long summons on it will do the effect I'm talking about.

[edited by - LlamaGuy on January 11, 2004 3:33:45 PM]

Screw it, I just decided to give in and redraw the scene twice. It''s quicker than I thought, my framerate is still higher than my monitor''s refresh rate.