High speed animation - help needed

(Rotwang) #1

Hi, I’ve been having a lot of trouble producing AVIs in Blender and wondered if anyone could help.

I’m producing animations of vehicles and aircraft with fast moving propellers and stuff, and I can’t get a decent looking animation out of them.

The animations I keep producing are often ridiculously slow, and have a very low number of frames per movement, so everything looks jerky, especially propellers and the like.

I’ve tried tweaking the map old and map new values (though I don’t know exactly what they do - the manual is rather vague about these), and though I’ve managed to increase the number of blender frames in the movement, everything now plays much slower in the rendered AVI.

I can’t find out anywhere what the various animation parameters and controls do, and what sort of settings I should use for which applications. Frame rate, field rendering, animation speed, I need help and suggestions on how to use them properly.

In particular, the frames/sec setting in the view buttons window doesn’t appear to do anything at all.

If you would like the Blend file to look at to see what settings I’m using at the moment, email me and I’ll send it to you.


(VelikM) #2

Set the rotation of the prop to 2000-3000deg/25 frames and use motion blur. Props spin fast/lots of deg/sec, an airplane prop spins at 2000 to 3000 rpm thats 33 to 50 revolutions per sec or 11,880 to 18,000 deg/sec the settings in Blender are for degrees of rotation/frame so to get something to spin fast you need to bump the deg/frame.
Play with the settings until you get a decent effect.

(mrunion) #3

Also make sure you are not saving your AVIs in RAW format/ They are HUGE and SLOW that way. Try using DivX or something to compress them and see if it runs faster.

Obviously you still need the motion blur/degrees-per-frame stuff mentioned above.

(Rotwang) #4

That’s not the problem.

These props are airship props, and don’t go particularly fast - they’re qite slow enough to see the individual blades moving.

When you advance the frames by pressing the right arrow key in the view window, the whole scene moves smoothly and at an acceptable speed. It’s only when the avi is produced that it gets jerky. (I’m using JPEG compression at the moment)

There’s almost certainly something wrong with the settings for the output file, but I don’t know what.

Shall I email somebody the file so they can see?

(banana_sock) #5

are you playing the avi in blender? cos avi doesn’t play very well in blender’s player.

(meestaplu) #6

I have one question first:

  1. What framerate you are using? NTSC video (TV in the United States) is 30 frames/sec and film runs at 24 frames per second.

If the framerate isn’t your problem, then there could be a couple of things.

First of all, AVI JPEG can be pathetically slow and jerky to play, especially if you have a slower processor and the file is long. The decompression process is very CPU intensive. On my Athlon 1200 it will periodically slow down (although very infrequently).

Secondly, when you play a movie in Blender the numpad will affect how fast it plays. 5 is a middle speed, 9 is REALLY fast, and 1 is slow. Try playing it really slowly - the framerate will make it look a little choppy, but the propeller should turn at a constant rate as the frames advance.

Good luck.