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terrain render

Started by germangb Dec 10, 2012 at 6:00 PM 6 replies 2.6k views
Original Post
germangb
germangb
Hey, I want to implement clipping in my terrain generator in openg.
The question is: would it be ok to use inmediate mode to perform the render?
germangb
germangb

Yes. viewport clipping still works in immediate mode IIRC.


won't it make the framerate drop drastically?
L. Spiro
L. Spiro
Using immediate mode makes slow.
It is never “okay” to use immediate mode.
Use VBO’s.


L. Spiro
I restore Nintendo 64 video-game OST’s into HD! https://www.youtube.com/channel/UCCtX_wedtZ5BoyQBXEhnVZw/playlists?view=1&sort=lad&flow=grid
germangb
germangb

Using immediate mode makes slow.
It is never “okay” to use immediate mode.
Use VBO’s.


L. Spiro


yeah I know, but what about displaylists instead of VBOs?
Krohm
Krohm
Display lists have been "discouraged" for a while. I stopped using GL years ago and they were already considered on their way out.
As far as I recall, they're now officially deprecated... except GL cannot say "deprecated", it says "not in the core profile" or something like that.
Previously "Krohm"
L. Spiro
L. Spiro
If your question is purely about whether or not viewport clipping is supported with each of these rendering methods, the answer is Yes. Viewport clipping is part of the rendering pipeline and it makes no difference how the triangles got to that stage of the pipeline.

But we can’t tell you in good conscience to use immediate mode nor display lists.
Immediate mode has been deprecated for ages and is terribly horribly slow. Display lists have been deprecated for a shorter period of time but are deprecated and their use is entirely discouraged not only by people who know what they are doing but also by Khronos. Considering how easy the switch is to VBO’s from display lists, there really is no reason not to do it, so I really can’t understand why you can’t just use VBO’s and be done with it.

In future versions of OpenGL you won’t even have the choice not to use VBO’s—it will be required that you do.


L. Spiro
I restore Nintendo 64 video-game OST’s into HD! https://www.youtube.com/channel/UCCtX_wedtZ5BoyQBXEhnVZw/playlists?view=1&sort=lad&flow=grid
germangb
germangb

If your question is purely about whether or not viewport clipping is supported with each of these rendering methods, the answer is Yes. Viewport clipping is part of the rendering pipeline and it makes no difference how the triangles got to that stage of the pipeline.

But we can’t tell you in good conscience to use immediate mode nor display lists.
Immediate mode has been deprecated for ages and is terribly horribly slow. Display lists have been deprecated for a shorter period of time but are deprecated and their use is entirely discouraged not only by people who know what they are doing but also by Khronos. Considering how easy the switch is to VBO’s from display lists, there really is no reason not to do it, so I really can’t understand why you can’t just use VBO’s and be done with it.

In future versions of OpenGL you won’t even have the choice not to use VBO’s—it will be required that you do.


L. Spiro


thanks! I'll definitely go with VBOs

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