This thread will slowly grow to become the FAQ for the OpenGL forum.
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questions and answers.
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someone answers it properly.
1. Isn’t DirectX better than OpenGL?
2. What is/How do I implement a certain feature in OpenGL or where can
i find good resources on that topic ?
3. What is VSYNC (Vertical Syncronization) and how do I turn it off in
4. Which is better: Normal glTriangle3f() calls or Vertex Arrays?
5. What is the difference between vertex arrays and vertex buffers?
Q1: Isn’t DirectX better than OpenGL?
This is a question asked in many different forms. Sometimes not even a
question. The simple answer is that neither is better overall. They have
different features and parts, but neither is better or worse. You’ll
need to find this out for yourself.
Q2 : What is/How do I implement a certain feature in OpenGL or where
can i find good resources on that topic?
The number one resource for you is google. Try
finding information through google first. This
might answer many questions you have much more complete than any of the
people around here could do in one post. Also you learn much quicker if
you find out about things yourself instead of asking for a ready
solution. If you can’t find what you want you are of course encouraged
to ask your OpenGL related questions here. In fact, if you can’t find
any resources about your topic on the web you might want to post a
suggestion for a tutorial or an article here: Article & Tutorial
Because devmaster.net is trying to present original and unique content
we always appreciate such suggestions.
Q3: What is VSYNC (Vertical Syncronization) and how do I turn it off
The refresh rate of the monitor is the number of times the monitor
“refreshes” the screen in one second. Most monitors have a refresh rate
of 85 Hz (Hz is a unit which is equivalent to 1/second). It is kind of
similar to frames per second. When VSYNC is on, your OpenGL application
will not draw faster than the monitor can handle. So if your refresh
rate is 85 Hz, you won’t be able to have more than 85 frames per second.
However, when disabling it, you remove that limit/restriction off, and
your OpenGL application will draw as fast as it can (basically you get
more than 85 frames per second). However, there is a tradeoff; when
disabling vsync, you get tearing or jerkness, which means motion is not
smooth. This is because your application is drawing faster than the
monitor can handle. Having vsync on will produce very smooth effects.
When debugging, you can have it off to test the performance of your
program (or even do benchmarking). For the final release of your
product/application, have vsync ON always to create maximum visual
To disable VSYNC in OpenGL, you will have to use extensions. Therefore,
your OpenGL driver must support it. Check this
Q4: Which is better: Normal glTriangle3f() calls or Vertex Arrays?
Vertex arrays are usually faster since they require little function-call
overhead. That is, using vertex arrays, only one call for drawing on
object is required.
However, for glTriangle3f, you will be required to call it multiple
times, which could present some performance costs. See this
Q5: What is the difference between vertex arrays and vertex buffers?
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