Direct 3d vs. Open Gl question

FredLocks

Member
Nov 5, 2001
185
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I just loaded up Serious Sam 2nd encounter and it runs great in open gl but is kind of choppy in direct 3d.
i'm running the game at 1600x1200 and 32 bit textures.
windows 98
AMD1800+
epox 8kha+
512 megs PC2100
geforce 3 ti-500
direct x 8.0

I'm just curious why Direct 3d doesn't perform as well as Open GL....Whats the difference between the 2?
thanks
 

DaHitman

Golden Member
Apr 6, 2001
1,158
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0


<< I just loaded up Serious Sam 2nd encounter and it runs great in open gl but is kind of choppy in direct 3d.
I'm just curious why Direct 3d doesn't perform as well as Open GL....Whats the difference between the 2?
thanks
>>



DirectX:
- propetary
- single vendor provided and controled
- single platform WINDOWS ONLY
- only does what microsoft says it can do
- only runs where microsoft says it can run
- does not implement all the functions of OpenGL
- fairly new and untested and is constantly changing because MS is still trying to catch up to OpenGL
- people complain its not the best to program in, the API call have been described as a bad copy of OpenGL
- has sound and input routines that OpenGL doesn since its just a graphics library... but there are other solutions that work great with OpenGL such as the SDL library to do the same thing
- Microsofts attempt to lock people into developing Windows only games that will not work on non-windows systems

OpenGL:
- industry standard by standard commite
- open to anyone to help set its direction and move it along, not just the whims of a single vendor
- runs on just about any platform that can draw a square
- been around for a LONG TIME and its VERY robust
- produces higher quality ouput.. In my opinion OpenGL usually just "looks" better
- By using it your not tied to a single vendor or platform
- By using it your not a slave to microsoft
- makes porting the same game to run on windows, mac, linux, playstation much much easier



 

BFG10K

Lifer
Aug 14, 2000
22,709
3,003
126
It's nothing to do with the API at all, it's simply the fact that Croteam have had more time to optimise their OpenGL renderer than their Direct3D renderer.

Generally speaking both APIs look good and run fast.
 

Cat

Golden Member
Oct 10, 1999
1,059
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DirectX:
check - propetary
check - single vendor provided and controled
check - single platform WINDOWS ONLY
check - only does what microsoft says it can do
check - only runs where microsoft says it can run
false - does not implement all the functions of OpenGL, but it is harder to extend
false - fairly new and untested and is constantly changing because MS is still trying to catch up to OpenGL <-- false!
false, especially with D3D8- people complain its not the best to program in, the API call have been described as a bad copy of OpenGL
check - has sound and input routines that OpenGL doesn since its just a graphics library...
false!!!- but there are other solutions that work great with OpenGL such as the SDL library to do the same thing
true :( - Microsofts attempt to lock people into developing Windows only games that will not work on non-windows systems

OpenGL:
- industry standard by standard commite
- open to anyone to help set its direction and move it along, not just the whims of a single vendor
- runs on just about any platform that can draw a square
- been around for a LONG TIME and its VERY robust
totally, utterly, false - produces higher quality ouput.. In my opinion OpenGL usually just "looks" better
- By using it your not tied to a single vendor or platform - YOU'RE
- By using it your not a slave to microsoft - YOU'RE
true - makes porting the same game to run on windows, mac, linux, playstation much much easier


The OpenGL D3D process goes like this
time----------->
OpenGL revised. Vendors expose functionality through new extensions
Direct3D revised. Vendors wait on a new version of Direct3D

At any point in time, OpenGL does not 'do everything Direct3D does', and vice versa.

Posting misinformation because you hate a company is not a nice thing to do.
 

FredLocks

Member
Nov 5, 2001
185
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0
So, it's just a case of the programmers spending more time optimizing the game for open gl? That seems odd, why even give an option of direct 3d if it is outperformed by open gl? BTW thanks for the responses.
 

Cat

Golden Member
Oct 10, 1999
1,059
0
0
Certain cards fare better better with Direct 3D than with OpenGL. SS is being ported to the XBox, which is Direct 3D only, so this might be another good reason to have the support in :)
 

Callred

Junior Member
Feb 10, 2002
5
0
0
It depends on a lot of factors. On my system, using the latest Det drivers from Nvidia, Serious Sam runs best in D3D and choppy in Ogl.
Unreal Tournament is NOW the same way under WinXp, whereas under Win2000 it was the reverse. Running a slightly older mainboard and cpu and video card, I still experiment with drivers like mad until I hot a set that give me the best balance for all my games, both Ogl and D3D.

Try a few settings in your display drivers or even different drivers and see what you get for results.

Luck
Cec