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Type: Posts; User: GeLeTo

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  1. Thread: Ptex extension

    by GeLeTo
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    Re: Ptex extension

    You can use HW filtering if you add a border around each subtexture with pixels copied from topologicaly adjacent subtextures. This has some drawbacks:
    - subtexture bleeding at low mipmaps
    - not...
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    Re: glBufferData variant with retained data copyin

    Yes, as I've mentioned above. But unfortunately it's not always possible. For instance I have a case where I need the generated vertex data to calculate the normals. Also I have several threads...
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    Re: glBufferData variant with retained data copyin

    The creation of the temporary buffer and the subsequent second copying (system mem to temp buffer to final buffer) are not no-ops.

    MapBufferRange with MAP_INVALIDATE_RANGE_BIT is very similar. The...
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    Re: glBufferData variant with retained data copyin

    There are usually two copies of the data - one in system , one in GPU memory. The best time to copy the data from system to GPU memory is right after the GPU has finished using the buffer. And only...
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    Re: True transparency

    This is unlikely, if the scene is too complex you may need too many passes but the used VRAM will be the same. You need two depth/color buffers instead of one. On current hardware it makes sense to...
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    Re: glBufferData variant with retained data copyin

    [/QUOTE]I have no idea what these "other synchronization techniques to ensure correct operation" could be, apart from glFlush. If you already know that the buffer is synced and safe to modify - you...
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    Re: glBufferData variant with retained data copyin

    "SGIX_async provides a way to allow certain OpenGL commands to complete out-of-order with respect to others. This extension does not by itself enable asynchrony;"

    Why not - this approach fixes...
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    Re: glBufferData variant with retained data copyin

    This may work. It will still use another buffer on the GPU and will require more work from the driver. Probably MapBufferRange with MAP_INVALIDATE_RANGE_BIT does something similar internally.
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    Re: glBufferData variant with retained data copyin

    No, I think you misunderstood what I proposed.
    glBufferDataRetained will return immediately and the driver will not wait for the data to be copied - it will know when the right time to copy the data...
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    Re: Official feedback on OpenGL 3.2 thread

    No.
    I am moving this discussion here:
    http://www.opengl.org/discussion_boards/ubbthreads.php?ubb=showflat&Number=261827
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    Re: glBufferData variant with retained data copyin

    I don't see how this can avoid syncing, unless using MAP_UNSYNCHRONIZED_BIT - but why would anyone use this?
    With my proposal - the driver will know best when the buffer is available and will only...
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    glBufferData variant with retained data copying

    I am moving this discussion here from the "Official feedback on OpenGL 3.2 thread" to avoid spamming it further.

    Here's the proposal:

    Jon Leech's reply:

    And my take:


    Some people suggest...
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    Re: Official feedback on OpenGL 3.2 thread

    No, I don't want that. I want a modification of glBufferData/glBufferSubData that will not copy the data right away but will return immediately and then the driver will wait for the GPU buffer to be...
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    Re: Official feedback on OpenGL 3.2 thread

    Which will cause glTexImage not to return untill the copying is done. Which is another thing that I want to avoid. And then there is glTexSubImage, which depending on how the driver works may stall...
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    Re: Official feedback on OpenGL 3.2 thread

    Straightforward usage pattern? Mapping a buffer to update data will most certainly lead to sync issues. Even discarding the buffer with glBufferData(, NULL) and updating the whole thing might not...
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    Re: Official feedback on OpenGL 3.2 thread

    Now that we have sync objects, the API to implement this functionality is a no-brainer, so I hope to see it implemented sooner rather than later.
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    Re: Official feedback on OpenGL 3.2 thread

    Ok, then lets call it glBufferDataRetained / glBufferSubDataRetained.

    Currently sending data to VBO (or any other buffer data object) works like this:
    1. Allocate and fill the data
    2. Give it to...
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    Re: True transparency

    The easiest way (that I know of) to sort the polygons perfectly is by using a BSP tree. There's no way to avoid artifacts when sorting polygons on a z-value.
    You only have to regenerate the BSP tree...
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    Re: Official feedback on OpenGL 3.2 thread

    Are there plans to use ARB_sync with VBOs?

    For instance after calling glBufferData - the data will not be copied immediately, and it can be safely changed or deleted only after the sync object is...
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    Re: GL_REPEAT on Cube Maps??

    Just make the planet mesh with the same topology as a subdivided box. This way you will have 6 grids and you can use normal texturing.
    The texture coordinates must match where the grids meet and you...
  21. Thread: glFX

    by GeLeTo
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    Re: glFX

    I know of gleffect - I think it used to be the semi-official implementation of glfx, but it hasn't been updated for almost 2 years - since the time Khronos took over glFX. It's still better than...
  22. Thread: glFX

    by GeLeTo
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    Re: glFX

    Collada/ColladaFX is the file format. glFX is the API that could be used to implement ColladaFX in your app.

    I have to support Collada in my application, and implementing ColladaFX is not that...
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    Re: Convert Bitmap to 3D Extruded Mesh

    No need to call names

    My first impression was that the software will output a terrain/heightfield-like mesh from a bitmap in which case fixing the normal would be easy (if normal does not point...
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    Re: Convert Bitmap to 3D Extruded Mesh

    This is not Advanced OpenGL question.
    Just flip the faces which normal does not point upwards.
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    Re: geometry instance (geometry shaders)

    I think this can be used to draw HOS? Can I put the series of 16 bezier control verts in the slow stream and the tessalated vertex grid(as s and t patch coordinates in the 0-1 range) in the fast...
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