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raydog

OpenGL Drawing a grid

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raydog    102
Help, my brain is fried. My buddy needs some code to draw a bounded 3D grid (no poking end lines) with different colored major and minor ticks in OpenGL, but not sure what is best way to do it using floats or ints.

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Guest Anonymous Poster   
Guest Anonymous Poster
Sounds like a homework assignment to me...

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FritzMar    140
personal choice if you dont need the percision of floating points dont use them the ints will operate faster but then again i cant rember if opengl uses floats for its api or not you should use whatever the api uses for storing numerical data for your grid :)

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Guest Anonymous Poster   
Guest Anonymous Poster
It's not that difficult a task, just requires you to think about it for a couple minutes... Which is why there aren't any tutorials on it.


glBegin(GL_LINES);
for (int x=-MAX_MAP_SIZE;x

That's basically it.. may not be 100% correct there, I just wrote that up off the top of my head but I'm running on 1 hour of sleep for the past 2 days so the top of my head may not be quite clear.

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stevo86    150
Sorry, wasn't logged in in my last post.

It's not that difficult a task, just requires you to think about it for a couple minutes... Which is why there aren't any tutorials on it.


glBegin(GL_LINES);
for (int x=-MAX_MAP_SIZE;x<MAX_MAP_SIZE;x+=GridSize)
{
glVertex3f(x, 0, -4096);
glVertex3f(x, 0, 4096);
}

for (int z=-MAX_MAP_SIZE;z<MAX_MAP_SIZE;z+=GridSize)
{
glVertex3f(-4096, 0, z);
glVertex3f(4096, 0, z);
}

glEnd();

That's basically it.. may not be 100% correct there, I just wrote that up off the top of my head but I'm running on 1 hour of sleep for the past 2 days so the top of my head may not be quite clear.

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raydog    102
I'm just looking for grid drawing examples that are better written than mine given these parameters:
adjustable floating-point precision x,z stepping
adjustable floating-point precision x,z bounds
colored origin, major, minor lines

You have the idea, but it's too simple.

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Kelly G    358
Quote:
colored origin, major, minor lines

google glcolor , glLineWidth

Quote:

adjustable floating-point precision x,z stepping
adjustable floating-point precision x,z bounds

basic arithmatic?

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raydog    102
Somebody please move my thread to the Beginner's Forum, because no one here seems to take my question
seriously.

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Opwiz    348
Is this grid to be aligned with a certain plane (e.g. xy-axis) or span around the scene? Perhaps rendering a grid-box around the viewpoint is a good alternative, disable z-buffering when rendering to make it look like the grid is behind everything.

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raydog    102
What I would like to see is for you to submit your best 3D grid (xz plane) drawing routine,
bells and whistles, and I'll comment on it.

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Opwiz    348
Quote:
Original post by raydog
What I would like to see is for you to submit your best 3D grid (xz plane) drawing routine,
bells and whistles, and I'll comment on it.

I don't have any 3D grid drawing routine. Why don't you try implementing one yourself? I'll be happy to comment on it.

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stevo86    150
Quote:
Original post by raydog
What I would like to see is for you to submit your best 3D grid (xz plane) drawing routine,
bells and whistles, and I'll comment on it.


Why would anyone want to do that... Grids are boring in all sense of the word. They're easy to program, they look boring, and ... well that's it. There's no point in this, your question's been answered like 4 times and if you still can't figure out how to draw a grid, go read some NeHe tutorials, I'm pretty sure he's got a grid tutorial.

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