Part of the Khronos Group
OpenGL.org

The Industry's Foundation for High Performance Graphics

from games to virtual reality, mobile phones to supercomputers

Search:

Type: Posts; User: STTrife

Page 1 of 2 1 2

Search: Search took 0.00 seconds.

  1. Replies
    2
    Views
    538

    Length of ray under/above water

    Hi there,

    In my project I started out with transforming positions and normals into world-coordinates, but I was recently suggested to just use eye-space instead. Now I run into the following...
  2. Replies
    4
    Views
    511

    Ok thanks for the suggestions. I noticed that...

    Ok thanks for the suggestions. I noticed that world-space is not really a much used space in shaders, and the point about tiny world seems to clarify why that is. But for things that I do in the...
  3. Replies
    4
    Views
    511

    Hi Dark Photon, Some background: -I need flat...

    Hi Dark Photon,

    Some background:
    -I need flat shading
    -I want to generate the normals in the shaders (I might change this later, but let's assume that I need it for now ;)
    -I need the normals...
  4. Replies
    4
    Views
    511

    Normals using dFdx and dFdy

    Hi there,

    For my deferred rendering shader, I need to render the normals in world space to a buffer. When I was just working with creating terrain, I used this and it worked fine:

    in the vertex...
  5. Thanks, I read and think I understand the...

    Thanks, I read and think I understand the formulas that opengl uses, that was very helpful. I have also ensured that the render order of the layers is correct, but my question is now more general:
    ...
  6. I see.. yes this is exactly what I need, thanks!...

    I see.. yes this is exactly what I need, thanks!
    I suppose GL_FUNC_ADD would be appropriate for the first argument? If I use SRC_ALPHA and ONE_MINUS_SRC_ALPHA in the blending function?

    or...
  7. that is it, thanks! Actually: In my situation...

    that is it, thanks!

    Actually: In my situation ideal would be: overwrite alpha (with source alpha) if it's larger than the destination alpha, but I don't think that is an option in OpenGL, is it???...
  8. Blending on render to texture alpha problem

    Hi there,

    For a GUI system I render parts to a buffer/texture first (I call them a canvas), and then rendered the texture to the screen.

    For example

    -create buffer/texture
    -draw rectangle...
  9. Nice ideas :) I'll think I go for the first one.

    Nice ideas :) I'll think I go for the first one.
  10. Thanks, that was very clear. Is there a good way...

    Thanks, that was very clear.
    Is there a good way then to find out the distance perpendicular to the line segment of the fragment in the fragment shader? That seems neccesary for anti-aliassing or...
  11. rasterization and fragment coordinates for lines

    Hi there,

    I've been reading a bit about using lines in openGL, but it's not quite clear to me yet how they work in the fragment shader. Specifically I don't understand how the 3d fragment...
  12. Replies
    11
    Views
    3,216

    Yeah I get the idea :) I just looked in the...

    Yeah I get the idea :) I just looked in the manual / specifications, there are 107 instances of the word 'undefined' in there :)
  13. Replies
    11
    Views
    3,216

    I am testing with AMD radeon 6800 here. I guess...

    I am testing with AMD radeon 6800 here. I guess the tricky thing is that 'undefined' behavior does not produce any errors. So I was very surprised to see the terrain rendering in buffer 3, while I...
  14. Replies
    11
    Views
    3,216

    Thank you, it was indeed the alpha test!

    Thank you, it was indeed the alpha test!
  15. Replies
    11
    Views
    3,216

    to be more precise: this void main() {...

    to be more precise:

    this

    void main()
    {
    gl_FragData[0] = vec4(0,0,0,0.1);
    gl_FragData[1] = vec4(0,0,0,0);
    gl_FragData[2] = vec4(0,0,0,0);
    gl_FragData[3] = vec4(0,1,0,1);
  16. Replies
    11
    Views
    3,216

    if that is so, which I think would be very...

    if that is so, which I think would be very logical, then I don't understand this:

    In a shader to draw water:



    in the shade that renders the screen:
  17. Replies
    11
    Views
    3,216

    Hi arekkusu, thanks for your reply, most of it...

    Hi arekkusu,

    thanks for your reply, most of it makes sense now. Only thing is that don't understand why the alpha I write to buffer 0 effects the other buffers as well. How exactly does that...
  18. Replies
    11
    Views
    3,216

    selectively writing to buffers

    Hi,

    I ran into something weird, or something that I don't know how it works exactly.

    What I want to do when rendering to multiple targets is that I selectively write to certain color buffers...
  19. Replies
    20
    Views
    3,317

    thanks this is really helpful, will probably save...

    thanks this is really helpful, will probably save me some 'bug' tracking in the future too :)
  20. Replies
    20
    Views
    3,317

    hm hm trying to understand it here, most of it...

    hm hm trying to understand it here, most of it seems to make sense. But the part about adjecent pixels: the texture coordinates you talk about, are those the UV parameters on the primitive, or are...
  21. Replies
    20
    Views
    3,317

    I finally found it. In the 3D texture that I use...

    I finally found it. In the 3D texture that I use for fog, I set the min-filter to LINEAR (or NEAREST is also fine). It was default set to GL_LINEAR_MIPMAP_LINEAR by OpenSceneGraph.
    Can someone...
  22. Replies
    20
    Views
    3,317

    Exactly my thought, it almost HAS to do with...

    Exactly my thought, it almost HAS to do with something like that, because it happens at the edges of objects. Any other ideas or good ways to look into it are appriciated!
  23. Replies
    20
    Views
    3,317

    well it *should* be no aliassing. I use OSG for...

    well it *should* be no aliassing. I use OSG for rendering, and I read this in a OSG mailing list .
    And indeed when I add the texture as a render target there are arguments how many samples it should...
  24. Replies
    20
    Views
    3,317

    I use this: if (length(normal)==0) //sky {...

    I use this:


    if (length(normal)==0) //sky
    {
    gl_FragColor = vec4(0.90, 0.82, 0.47, 1);
    return;
    }

    But I noticed the strange effects are also on hilltops that are not on the edge with the...
  25. Replies
    20
    Views
    3,317

    The format I use is GL_RGB32F_ARB. I use OSG, so...

    The format I use is GL_RGB32F_ARB. I use OSG, so this is what I use:


    osg::TextureRectangle* positionsRect;
    positionsRect = new osg::TextureRectangle;
    positionsRect->setTextureSize(screenWidth,...
Results 1 to 25 of 46
Page 1 of 2 1 2