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Strange Display ??

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15 comments, last by daviddiligent 16 years, 3 months ago
Sorry, didn't expect a response so quick...I tried to edit..

as for
"Another issue is that, I noticed that in my new system (which has the ATI HD 2900 Pro graphics card one), the moving targets are performing little jump effect. For example, if there is a blue-face moving from left to right, it doesn't move smoothly. but it moves smoothly to the right, then a little jump to the right, then smoontyly again, then a little jump again...."

Your graphics card should VERY EASILY handle what you are rendering. If for some reason its a FPS issue, it shouldn't be the card. Are you sure your not running anything in the background? Are you running a copy of the example program or something you wrote like it? If its your own, can we see your render loop? Are the jumps at predictable times (as in, once per second/5 seconds) or just randomly?

I admit it is weird you are seeing this jump in the movement.
my blog contains ramblings and what I am up to programming wise.
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Quote: Original post by daviddiligent
Another possible reason might be that, the other day, I was looking for the OpenGL SDK. The only thing I found is called OpenGL95.exe. I run it and it self-extracted to somewhere. I might change all my VC8 opengl sdk to this old OpenGL95 sdk. This might be the problem? If so, how can I possible get my VC8 opengl sdk back?


OpenGL95.exe installs openGL on computers running windows 95, any windows operating system after that has it as default.
It should be pretty much what VC8 has but with more bugs.


Anyway, it's probably running to fast, just add Sleep(5); after the swapbuffer command and it will probably run smoother.
Thanks im_gelling & ic_overload's replies.

The FPS of my new computer is more than 2500 for Lesson 32, which is still increasing slowly. (The way I used to compute the FPS is learnt from SDL tutorial).

One thing is very strange is that WHEN I ADD Sleep(5) after the SwapBuffers(), I then could see the Explosion effect(which I couldn't before). The only reason I can think of is because of the Pick Matrix (or Select) conflicts with something somewhere.

Also, after I added the Sleep(5), the choppiness problem remains, but have been greatly reduced.

Sigh....
/*----------------------------------------------------------------------------------------------------------------------------------*/Enthusiastic and wild about game development. Any opportunity would get me sink into any fantastic game-revolution era.
The reason you couldn't see the explotin effect is that it is not time dependent, instead it advances one frame each rendered frame.
So if your frame rate is around 2500FPS and the animation runs at 64 frames the entire animation will be displayed for about a 40th of a second, and with a refresh rate about 75-85Hz your lucky for it to be displayed for 1-2 frames.

with Sleep(5); your limit the fps to just shy of 200 FPS meaning it runs for about a quarter of a second or longer, that's why you can see it now.

If you want you could try to increase the sleep time to 10 or so (activating v-sync will work as well), but ultimately you need to convert all animation and motions to time based animation instead of frame based ones.
Just look at it as extra homework from me to you.
Quote: Original post by lc_overlord
The reason you couldn't see the explotin effect is that it is not time dependent, instead it advances one frame each rendered frame.
So if your frame rate is around 2500FPS and the animation runs at 64 frames the entire animation will be displayed for about a 40th of a second, and with a refresh rate about 75-85Hz your lucky for it to be displayed for 1-2 frames.

with Sleep(5); your limit the fps to just shy of 200 FPS meaning it runs for about a quarter of a second or longer, that's why you can see it now.

If you want you could try to increase the sleep time to 10 or so (activating v-sync will work as well), but ultimately you need to convert all animation and motions to time based animation instead of frame based ones.
Just look at it as extra homework from me to you.


Thanks for explaining the lack of "Explosion Effect". It's been really helpful :)

However, the movement of the objects (such as the blue-face) is dependent on time, i.e. inside of the update(Millisec), all the objects coordinates and spins are set. But the results of the moving objects show the choppiness somehow. I can't explain this.

Last but not least, thanks for ur coursework. The lesson32 is based on timed animation, isn't it? :)

Cheers
/*----------------------------------------------------------------------------------------------------------------------------------*/Enthusiastic and wild about game development. Any opportunity would get me sink into any fantastic game-revolution era.
Lesson32 should be mostly timed animation save for the explosion that is.
Choppiness in a otherwise smooth motion is often the work of other applications or even the OS updating something every now and then, it's often not that bad unless you run something that goes ultra fast and smooth that is, and it's all CPU based.
I had a bad case of this on an old p4 3,05HT at school until we upgraded to XP pro sp2 that could take advantage of the two virtual cores, after that we had no more severe choppiness, of cause there will always be some and you just have to ignore that.

Today i have a quadcore, so no more choppiness for me, even if i wanted to.
Cheers Ic_overload

By the way, in terms of time-based animation, the follow code should be working fine, right? I.e. if I pressed the S button, the plane will move vertically smoothly according to the lapsed milliseconds.

void Update(DWORD milliseconds){  ...  myPlane->speed=200.0f*((GLfloat)milliseconds)/1000.0f;	  if (g_keys->keyDown['S'] )       myPlane->y += planeHost->speed;  ...}


Again, it moves smoothly in my old computer, but a little choppiness in my new computer, even if i add a little sleep(whatever-millisecond). :(
/*----------------------------------------------------------------------------------------------------------------------------------*/Enthusiastic and wild about game development. Any opportunity would get me sink into any fantastic game-revolution era.

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