spline motion blur on 1st frame

[iishohin]

hi.

recently i had to roto a sequence whose 1st frame had some motion blur on it. when i switch the rotospline motion blur on, quite understandably the blur starts on frame 2. ideally i would have liked it to start from the 1st frame.

So is there any workaround that will for example let me position the spline on a 0th frame so that the 1st frame can have blur applied?

thanks in advance

[J Bills]

sure – reexport your clip with a blank frame 0. Motion blur needs that frame before/frame after to work properly, so just feed it another frame.

Or, you can export the matte and hand paint the blur using the paint tools (either cloning from frame 2 or just blurring by hand).

[iishohin]

thanks for the suggestion.

i knew i could re-export the clip with the extra frame, but i thought that for such a basic but important thing as applying blur on the first frame could be done in a less hard-disk-hungry and simpler fashion. Painting, in the case i am working on would be impractical.

Does the SilverMan have any thoughts on the matter?

[Matt Silverman]

[J Bills] “sure – reexport your clip with a blank frame 0. Motion blur needs that frame before/frame after to work properly, so just feed it another frame.

Or, you can export the matte and hand paint the blur using the paint tools (either cloning from frame 2 or just blurring by hand).”

😉

[J Bills]

ha!

you might also try adding a keyframed directional blur on the matte render, that is only present on frame one and then keyframed to “off” on frame 2. That might be a good cheat.