Vertex normals, hardware determination, VRAM

OpenGL OpenGL: Basic Coding
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A few quick questions:

  1. I understand a plane normal and what it means. I don’t quite understand how a single point can have a normal though. Right now I’m just making each polygon’s vertex normal equal to the polygon normal, but it results in flat shading (obviously). How do I generate a normal for a point… is it an average of all the polygons’ normals that share that one vertex?

  2. How can I find the name of the video card under Windows (for bug reporting purposes)?

  3. How can I find how much V(ideo)RAM is left?

  4. I’m using NeHe’s tutorials and am having the problems with ATIs and Voodoo cards (like it appears everyone else is). I’ve done some searching but haven’t found a clear answer to it yet. Any pointers?

Thanks =)

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  1. yes. There are some ways doing this. Simplest is to add all and then normalize the resulting vector. But you can for example also take the poly’s size in account.
  2. There are some descriptions that you can get through glGetString (or how is it called?), check for GL_VENDOR etc.
  3. DirectX can, I believe, but I think it’s senseless anyway.
  4. 3dfx sucks. Which card do you have?
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I’m using a TNT2 card without any problems; however, when I give my demo to friends with a Voodoo 3 card, it crashes in fullscreen mode. After posting my message, I read about finding the 3dfxgl and dynamically linking to that instead, etc, so I suppose I’ll try this.

Thanks for your other answers, that’s exactly what I needed to know =)

  • Jeramie