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Type: Posts; User: john

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  1. Replies
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    Re: Transparency CBuffer

    Sorting based on primitive is, after all, the painter's algorithm and so of course this problem comes up. It's why z-buffers are used instead; but z-buffers only became practical when using that...
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    Re: Transparency CBuffer

    I am just musing, here, but would you need to use a linked list *per pixel*? What about having OpenGL maintain sorted *primitives* that are order dependent (n.b. not all blending IS order dependent)...
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    Re: latest nvidia drivers (8756)

    Hi,

    I am having issues with 8756 drivers and glXChooseFBconfig. It returns a NULL list of supported pixel formats. glXChooseVisual works, though, but that's not the point when it can't support...
  4. Thread: SLi

    by john
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    367

    Re: SLi

    Hello,

    OK, I've found the answer. For completeness, it is:

    http://download.nvidia.com/XFree86/Linux-x86/1.0-8174/README/32bit_html/appendix-w.html

    cheers,
    John
  5. Thread: SLi

    by john
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    367

    SLi

    Hello,

    does anyone know how to configure SLi under Linux?

    I'm interested in using both cards with SLi, but also in disabling SLi so I can use the two cards independently (ie. localhost:0.0...
  6. Thread: scene graph

    by john
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    Re: scene graph

    Hi,

    you'll still have significant problems with latency, even (!?) if you clip the scenegraph on the server and send a subset. While the server is traversing the scenegraph and packing it into a...
  7. Re: Could someone please explain post/pre multiplication & column/row major matrices?

    Hello,

    the reason why the translation is 'called' first, if you like, is because OpenGL *post* multiplies the matrix stack. Here's a simple example using translation and scalking. Suppose the...
  8. Re: Could someone please explain post/pre multiplication & column/row major matrices?

    Hi,

    you're right: matrix operations are NOT commutative (ie. AB != BA for all A, B). OpenGL matrix operations are post-multiplied. For example,


    glLoadIdentity();
    glRotatef(...);...
  9. Re: What do I need to start programming in OpenGL with plain C?

    An exercise for the reader: take the OpenGL API and remove all the pages in it that relate to C++, and learn from that.

    Your common, or garden-variety, OpenGL library exports C symbols; there is...
  10. Thread: Ying yang symbol

    by john
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    Re: Ying yang symbol

    > But what's the link with GL ?

    glBegin(GL_TURTLE);
    glVertex2f(0, 0);
    glForwardf(100.0);
    glRotateTurtlef(50);
    glForwardf(50;0);
    glEnd();

    // etc.
  11. Replies
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    Re: 3D stereo application help.

    Hi,

    since your eyes are actually focusing on the computer screen, you need to model your virtual cameras as focusing on some plane in world space. Consequently, any point in world space on the...
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    Re: Rendering Algorithm

    Hi,

    that's not the bottleneck---that's the SYMPTOM of the underlying bottleneck.

    Ergo, further investigation is required!

    cheers
    John
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    Re: hInstance error when compiling.

    Hi,

    you need to create an object named hInstance. If I was a betting man, I'd guess you'd want to declare it in your WinMain prototype, like so:

    ...
  14. Thread: shape fitting

    by john
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    Re: shape fitting

    this is an Np-complete problem...
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    Re: matrix manipulation optimization

    and for extra marks, "how long is this piece of string"?
  16. Re: Does OpenGL remove the processing of the objects that aren't in the view volume?

    The answer is, of course, that OpenGL has to do SOME processing for EVERY vertex you give it. Vertices that are clipped because they fall outside the view frustum have less processing than those...
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    Re: Making an isometric view

    why yes... yes, it is.,

    but since you know what you want, the question really is: is this what you want?

    as i said in my post, your house is aligned with the y axis==depth, which is probably...
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    Re: Making an isometric view

    glLoadIdentity ();
    // gluLookAt (12., 10., 10., 5., 0., 5., 0., 0., 1.);
    glPushMatrix ();
    glRotatef(-45.0,1.0,0.0,0.0);
    glRotatef(-45.0,0.0,1.0,0.0);hi,

    ok, so I compiled it and tweaked it. ...
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    Re: Making an isometric view

    yes

    you're using glLookat. That's throwing away any isometric transformation you set up.

    cheers
    John
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    Re: Making an isometric view

    Hello,

    you need orthogonal projection and more likely rotate the scene by 45 degrees about the Y axis and the X axis.

    cheers
    John
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    Re: ATI Linux driver crash on exit w/ GLSL

    But where's your distinction? On one hand, a library is just a part of an application that's generally intended to be reused; but on the other hand, it's *just* a collection of object files. ...
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    Re: ATI Linux driver crash on exit w/ GLSL

    Hi,

    but it's not really an issue of saving typing, it's an issue of making sure resources are released.

    For example, suppose I come up with some library that has static variables that need...
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    Re: ATI Linux driver crash on exit w/ GLSL

    well, why not? it's functionality is well defined (it executes when main() exits and before the executable's prologue) and it's standard. You may as well say you don't use for() loops unless you're...
  24. Re: Switching Between Orthographic and Perspective Views

    do you then redraw the screen? Changing the projection matrix won't suddenly change what has already been drawn; you have to repaint the screen to see any new effect.

    cheers
    John
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    Re: reshaping a window in orothographic view

    orthographic projection defines a set of lines on the XY plane defined by x=left, x=right, y=top and y=bottom. The trick, then, is to work out how you want your viewport with some width/height to...
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