PDA

View Full Version : Renders well when small and simple, incompletely when large and complex



PeterK
05-22-2000, 11:10 AM
I am writing a multi-window MFC application in VC++ 6.0 that has a problem. http://www.opengl.org/discussion_boards/ubb/confused.gif

Problem Details

1) Rendering in small windows works well but if the window is maximized (or expanded beyond a certain size) the rendering is incomplete:

- some of the polygons composing a surface become visible (black lines of the polygons streak the surface)
-the rendering speed slows way down (redraws take a long time)

2) This problem only occurs when the scene being rendered is sufficiently complex(when using solid polygon mode and the viewport is large).

3)If a window that exhibits the problem is resized back to a smaller size, the problem (black polygon lines, slow rendering speed) does not go away.

4)If a single window is being rendered well (at a size just below the critical size that triggers the problem) and a new window is created, the new window will have the problem (although it wouldn't if the first window were smaller).

Environment Details

I am using NT 4.0 on a 400MHz computer with 64MB and a (ugh) 4MB ATI 3D Rage Pro graphics card.

I have used the standard document/view architecture and have followed examples of how to use OpenGL with MFC.

How can I fix this problem that renders large, complex scenes incompletely?

sebastian
05-23-2000, 02:35 AM
hi Peter,

i share your problem... --> ATI 8MB
if i had mo' money and time to code openGL stuff,i surely would buy one of those killer cards..
i don't know if you have some bugs in your app which slow down the whole thing,but i think it's just a matter of card/drivers...
good luck for optimizing your stuff http://www.opengl.org/discussion_boards/ubb/smile.gif

Kaeto
05-23-2000, 05:37 AM
Your video card doesn't have enough memory. I wouldn't (in fact, I don't, I have one on another box) take any 4mb card past 640x480... 800x600 will work, but it'll tend to be a tad slow because of textures being loaded and unloaded...

Kaeto
05-23-2000, 05:40 AM
Oh, just in case you were wondering, it seems like your driver is switching to software rendering on the fly, but it can't/doesn't switch back...

PeterK
05-23-2000, 07:09 AM
Thanks for your help -I was really puzzled. I'm going looking for a new video card (any suggestions?).

Eric
05-23-2000, 08:07 AM
Go for a GeForce256 DDR. As the Geforce2 GTS appears on the market, their price should drop down quite significantly.

I have been using an ELSA Erazor X2 for 3 months now and it really ROCKS !

If you are looking for a professional accelerator, I can't be of any help !

Regards.

Eric

Kaeto
05-23-2000, 09:32 AM
I recommend a GeForce DDR, too, but they're still kinda expensive... Whatever you do, don't buy a video card at some freaking store. They charge soooo much. Get it from egghead http://www.opengl.org/discussion_boards/ubb/smile.gif

Humus
05-23-2000, 12:23 PM
It may also be worth taking a look at ATi's upcoming RADEON chip ... i think it's gonna kick ass ...

MikeC
05-24-2000, 08:18 AM
On paper, yes. I suspect it'll be a fair while before their OpenGL drivers can match NVidia's though.

PeterK
05-25-2000, 06:41 AM
Any ideas about a good-for-its-price (relatively cheap) OpenGL card?

Eric
05-25-2000, 06:45 AM
PeterK, I am not sure of what you mean by OpenGL card (i.e. Consumer or Professional level ?).

As I said before, for consumer level, GeForce is very good but, as it was pointed out, it is still very expensive...

Before buying the GeForce, I used a Diamond Viper 770 Ultra based on the TNT 2 Ultra and I was very happy with this one as well.

So, to make a long story short : for consumer level, buy a GeForce DDR if you can afford it or a TNT 2 Ultra if you are tight on money... (and no no no, I do not work for nVidia (yet?!?)).

Best regards.

Eric


[This message has been edited by Eric (edited 05-25-2000).]

Kaeto
05-25-2000, 08:29 AM
Or a *ducks* Savage2000...
Hey, I like the card! It's fast, and the GL drivers are pretty good. The card isn't the best for D3D, but who cares http://www.opengl.org/discussion_boards/ubb/smile.gif And you can get 'em for $130 at egghead, cheaper other places http://www.opengl.org/discussion_boards/ubb/smile.gif

Humus
05-25-2000, 10:55 AM
MikeC:
Yes, this is my worry too. It seams to have every single feature possible in hardware, but ATi isn't exactly known for their excellent drivers ... so i'm gonna wait until there's some sort of proof that the drivers is good enough before i buy it (if i do). But they seamed to have put in some huge developer teams in the project so i have hope ...