problems with rpf camera import

[Mylenium]

ok so adobe for a long time have claimed you can import rpf camera data into after effects. but to me it is always innacurate. if i place something in 3d space at the same position as an original 3d object in the scene it always moves differently, and i get paralax errors. combustion does this much better, but what i wanted to ask is if there is a more accurate way for after effects to deal with rpf cameras, or have they fixed it in cs3?

Not sure what you mean. Many other users do this successfully each day. Depneds of course on what moves your camera actually makes and what your scene dimensions are, but beyond the usual scale problem in AE it shouldn't pose any problem. From what program are you rendering and what are your parameters?

Mylenium

[acgraham]

rendering from max 7, 8, or 9 ive seen this issue. render a box at 0,0,0 with size 20 units. move a camera all around the box off the side of the screen. try and position an after effects layer/point on one of the boxes corners and it will not stay exactly on there.

i render my rpfs with every setting turned on.

if i import the exact same sequence into combustion, i dont have any problems.

[acgraham]

i just remembered another question, can ae use occluded object information so you can see whats behind an object if you remove it?

[Mylenium]

rendering from max 7, 8, or 9 ive seen this issue. render a box at 0,0,0 with size 20 units. move a camera all around the box off the side of the screen. try and position an after effects layer/point on one of the boxes corners and it will not stay exactly on there.

i render my rpfs with every setting turned on.

if i import the exact same sequence into combustion, i dont have any problems.

Your dimensions are too small. 20 units would translate to 20 pixels and the camera moves would do the same. It's a mere precision problem due to quantization. also be aware that AE interprets RPF data as 8 bit int, not float or something, so this further compounds the error. You need to work with different scene scale.

As for your otehr question: No, occlusion/ obscuration buffers are not supported. RPF is more or less Autodesks own private format and thus many of its features are undocumented and not usable by third parties. It's completely bastardized and only works in their own products.

Mylenium

[acgraham]

thanks for the reply mylenium. about the accuracy problem, if your right, how come combustion can import rpfs without the accuracy issues then?

[Mylenium]

about the accuracy problem, if your right, how come combustion can import rpfs without the accuracy issues then?

It reads them as 16bit int or float. Camera data is always stored as float values, but AE's loader will truncate it to 8bit precision. So what was once literally infinitely precise gets clipped to 5 mantissa (digits after the point), resulting in the jumps and jitters we all loathe. Scaling the values before they are embedded is the only solution, so you move the precision before the point where it won't be clipped. Either scale the scene or adjust the value ranges in the camera buffer (if MAX allows that, sorry, don't know it that well).

Mylenium

[acgraham]

ahh. thanks so much for this useful information! now we shall see how i go tomorow when i put it into practice!

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