Real-Time Rendered Objects in Pre-Rendered Scenes?

mrbig · 2007-07-13T19:11:42

Hi! As the title says, I want to use OpenGL to render objects in real-time, and have them correctly interact with a pre-rendered scene, for now only visually. By that I mean, to at least give the resulting hybrid scene a correct sense of depth, that is, to have the real-time rendered objects drawn behind or in front of the pre-rendered objects correctly. I think a simple way of achieving this effect would be to render the pre-rendered scene (with OpenGL, of course) and keep its Z-buffer, then, when drawing the hybrid scene, to initialize the Z-buffer to that of the pre-rendered scene, and only then to draw the real-time objects. (The "camera settings" for both scenes would have to be the same, of course.) There's just one problem - I have no idea how to do that using OpenGL. That is, I don't really know what extensions I'm going to need or how to use them. How do I send the Z-buffer content from the GPU to the computer RAM so I could save it in a file? (Now that I think of it, I don't know how to do that for the color buffer either!) How do I initialize the Z-buffer of an OpenGL scene to whatever I want? Any help will be appreciated! Thanks.

Graphics and GPU Programming Programming OpenGL

Started by mrbig July 12, 2007 11:56 PM

10 comments, last by Hello Kitty 16 years, 9 months ago

mrbig

100

Author

July 13, 2007 11:07 AM

Uh... your link leads me back to this thread. O_O
Could you please show me how to create a texture with depth components from a 'float' array, or maybe point me to some useful document?
In fact, I don't know how to create any kind of OpenGL texture at all... the library I use does it for me. *BLUSHES*
Damn it... I'm stuck with this all day.
OpenGL makes the basic things even more basic and everything else a nightmare.
Several years ago I've done the same thing in software mode in about an hour. x_x

Hello Kitty

106

July 13, 2007 07:11 PM

Why not use opengl to render the "pre rendered scene"
Use opengl to render the multi-million polygon scene with pixel shaders, anti aliasing etc.
Sure it takes opengl a few minutes to generate such a complex color image, as well as the correct zbuffer, but thats ok.

Save both images, and then use them in your realtime project.

meow

-goodbye-

Real-Time Rendered Objects in Pre-Rendered Scenes?

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Real-Time Rendered Objects in Pre-Rendered Scenes?

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Reticulating splines