i keep reading about ogl extensions…
but doesnt this limit the program to that specific harware…
is it worth it.
what are the most used or “nicest”?
is that how you would take advantage of nvidia’s T&L?

well yes, it does limit to specific cards and drivers. but hey, if it’s there, then use it! set up global boolean variables that tell you if the extension is supported and then check to see if they are, and set these vars. to appropriate values. then just use if/then statements to make use of them. if they have the extension then use it else use some other means to get a similar effect. the all time classic is the use of multitexturing vs. multi-pass rendering.

You don’t need to do anything to make use of T&L in OpenGL, if it’s there it’s gonna be used automaticly.

Hi xerid,

I will just tell you about one example concerning the extensions : you might know that when using textures in OpenGL, the specular highlight is not computed : you have to render the scene twice if you want it to appear. Some drivers have got the “GL_EXT_separate_specular_color” extension which enables you to do the same thing in one single pass…

In all my programs, I check for the available extensions and, if this extension is there, I use it…

So my programs are not limited but the better your graphics card is, the faster the program runs !

Meanwhile, when it comes to more specific extension (GL_NV_texgen_emboss), it can restrict the use of your program !



Unfortunately making the best use of HW T&L requires using extensions unless you are using display lists.
Read the FAQ here: http://www.nvidia.com/Marketing/Developer/DevRel.nsf/FAQ_Frame?OpenPage

question: i heard, that on geforce256 HW T&L
will be shutdown, if you use more then 4 lights??? is that true ?

That’s a bunch of bull. This demo from nvidia is proof.

Well fenris, although the above statement is false, it is true that the more lights you enable, the less useful is the HW lighting… It has been tested by various web sites since the GeForce has been released. Enable more than 4 lights, and HW lighting is not that good…

Concerning the demo you point out, let’s remember that GeForce only has 8 HW lights and not 70… (Well, you probably knew that !).