PixelFragments



  • THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 04/09/2004 at 15:33, xxxxxxxx wrote:

    User Information:
    Cinema 4D Version:   8.503 
    Platform:   Windows  ; Mac  ;  Mac OSX  ; 
    Language(s) :     C++  ;

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    In ExecutePixel I would like to be able to change the weight of only some of the pixel fragments. The frag element of the PixelPost structure is defined as the current PixelFragment. It is actually a pointer to a list of fragments.

    Inside the fragment there is a 'next' and a 'cluster'. What does 'next' point to? What list? List of what? Next pixel's fragments?

    What does 'cluster' point to? Is it the current pixel's fragments? Is there an order to the? Possibly z-depth?

    Which fragment is really the current fragment associated with the current ray intersection? ( seems ExecutePixel is called multiple times for the same pixel if the are multiple intersections )

    Is it possible to change the weight of a given fragment ( if we can find the one associated with current evaluation ).

    Put an effort towards this and found what I thought was true seems not so. Any insight is appreciated.

    Best Regards,
    darf



  • THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 09/09/2004 at 13:32, xxxxxxxx wrote:

    Howdy again,

    Really need help on this. If you cannot answer this knowing more about how to reconstruct an image from ExecuteLine and the pixel fragments availabe through pp->frag would be very helpful. I can recreate the image but it is offset to the right half a pixel. Explanation or code on how to correctly combine those fragments to produce the image matching the original would be brilliant.

    Best Regards,
    darf



  • THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 10/09/2004 at 15:29, xxxxxxxx wrote:

    I'll answer the parts I (think I) know and continue investigating the rest:

    • To my knowledge 'cluster' isn't used. Is it ever non-NULL for you?
    • The PixelFragments are themselves links in a linked list, so next simply points to the next fragment for the pixel.
    • I haven't tested if ExecutePixel() is called twice here, but perhaps one of them is with valid_line=FALSE?
    • It is non-trivial to exactly reproduce the C4D output from the data in ExecutePixel(). For example, the results would have to be weighted and put into AA filters.
    • I beleive the fragments are read-only.

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