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John Swafford
06-08-2003, 08:28 AM
I'm a 3ds max user trying to solve an output problem. The solution I'm looking for is conceptually rather simple, but it doesn't look like either After Effects or Combustion will do it. Here it is:

I want to process output frames from 3ds max in a way that evenly blends frames 1-10 into output frame #1, then frames 11-20 into output frame #2, frames 21-30 into output frame #3, and so on.....

I need to have all 10 frames in each set blended with equal weight into each output frame, but neither After Effects nor Combustion seem capable of it. In both apps, I've changed the frame rates/durations of the clips to run at 10x normal speed and enabled frame blending.

Although After Effects does sample each frame, it weights the frames being sampled like a bell curve....those input frames at the center of each frame interval are given more opacity in the blending than the rest. Combustion doesn't even try to blend frames when the footage speed is set to an even speed such as 1000%. If set to an odd speed like 991%, Combustion will blend frames using uneven weighting and only samples two input frames at a time.

Am I missing something? The help files for both apps do not lead me to think that they are capable of it, but this seems like such a simple task for 2D post software.
BoERS
06-08-2003, 04:09 PM
OK.... I haven't tried this... but in theory it will work.
<EDIT> Just tried it... works beautifully. </EDIT>


Take your layer, and duplicate it 9 times, for a total of 10.

Now leave the bottom layer's in point where it is, and shift the rest of the layer's in points one frame the the left of the one below it (see image).

Set opacity of the bottom layer to 100% (1), next up to 50% (1/2), next up to 33.33% (1/3), next to 25% (1/4), and keep going with this pattern all the way up (see image).

Should now look like this:

http://homepage.mac.com/reitsma/test.jpg

Pre-comp all of these layers, and then time strech the comp to 10%... Make sure to turn frame blending off.

:beer:
John Swafford
06-10-2003, 07:15 PM
Well, I was right: not a simple task. ;) Thanks for posting the opacity values. I'd always guessed that using the fractions 1/2, 1/4, 1/8, etc. was the way to go.....didn't think of using 1/2, 1/3, 1/4, 1/5, etc., but it makes sense.

The lack of any other posts here does answer my question: There isn't any easy way to do this. (I'm lazy.....I was hoping for a check box.) I'm going to be processing many different sequences of various lengths, as well as various frame rates (e.g. 10x, 30x, 50x, etc.) There is a way to do what I need using Video Post in 3ds max, but its fairly cumbersome and complicated. Easier than this, though. I might have to dabble in MAXscript to automate some of this....Crap!
gmask
06-10-2003, 07:35 PM
I don't see what is so difficult about the example given above..

Did you know wthat once you have setup such a comp that you just have to select the layers and hold down alt while dragging and dropping the new clip into the comp and it substitutes the new file for the old one. is that automated enough?
BoERS
06-10-2003, 09:32 PM
It really isn't difficult at all... As you can see, there is a difference of about 10 mintues between posting originally, and editing it to say it worked well... That also included a few other edits to format it a bit better....

Overall, I'd say it took me about a minute... maybe 90 seconds... No biggie.

It's definitely easier than dabbling in the MAXScript... and you can also change this afterwards if you need to, it is not set in stone.
Sherif.Nagib
06-17-2003, 01:00 AM
ehm..
a bit embarrassed to ask..but as a noob i'm keen to know..but about the blending.. it is about mixing layers with even or different opacity values ..right ??..so what kinda case needs so complex blending like that ??.. i guess the result will be like having motion trails..right ??

p.s ; plz correct me if i'm wrong (& i'm sure i am ) about any of the mentioned hypothesises
gmask
06-17-2003, 03:52 AM
Originally posted by achilles81
ehm..
a bit embarrassed to ask..but as a noob i'm keen to know..but about the blending.. it is about mixing layers with even or different opacity values ..right ??..so what kinda case needs so complex blending like that ??.. i guess the result will be like having motion trails..right ??

p.s ; plz correct me if i'm wrong (& i'm sure i am ) about any of the mentioned hypothesises

Well normally what frameblendin gin AE does if you use time remapping or time stretch is that it will blend frames by mixing them or it will try to mix the frames using fields.

I think the effect that the OP is going for is some sort of trail effect.. which there is actually a filter for but I think he is looking for a specific amount of control that the filter and frame blending does not provide.
BoERS
06-17-2003, 06:00 PM
I think the effect that the OP is going for is some sort of trail effect..

Yeah... more or less... (I think) he is trying to emulate the effect of motion blur. I have also done this, as Max, Cinema, and the like, do have some advanced motion blurring built in. We want to be able to render out multiple passes, and that doesn't play well with motion blurring... :shrug:
Sherif.Nagib
06-17-2003, 06:09 PM
thanx gmask & sector996
gmask
06-17-2003, 06:56 PM
Originally posted by sector996
Yeah... more or less... (I think) he is trying to emulate the effect of motion blur. I have also done this, as Max, Cinema, and the like, do have some advanced motion blurring built in. We want to be able to render out multiple passes, and that doesn't play well with motion blurring... :shrug:

Oh well in that case what I prefer to do is to render those elements out with a byframe of .1 and then do a timermap to shorten the longer clip to the correct time and that works pretty well but requires the extra rendering time.
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