hello.
It’s my first anim. and I just realized that I cannot always use 25 fr/sec.
If I pan the camera or an object moves too fast I cause a little strobing effect, and I don’t want it.
Example:
A simple anim. with an object moving through the scene.
I made a 4 sec. animation with 100 tga images trasformed in DivX5.1 by Virtualdub.
I set FrameRate:25 in Virtualdub
25 frs/sec. = ugly strobing effect
I tried this :
map_old:1 map_new:2
animation: 200 tga
Framerate:50 in Virtualdub,
In this way my animation has the same lenght but with double frames (50frs/sec) and looks better.
That’s my question: during an animation do you continuosly change the frs/sec in every scene following the fastness of the action?
Which is the max frs/sec do you use?
Thank you
No, don’t change the framerate. Stick with the standard ones (24, 25, or 30), and most definitely don’t change framerates from one shot to another in the same project (I’m not sure if that’s what you were suggesting, it’s not even possible).
It sounds like the problem you’re having could probably be fixed with some motion blur. Press the MBLUR button in the display buttons. Basically what this does is render multiple frames for each frame of the animation, then composite them together so that it is blurred. The buttons under the OSA button (5, 8, 11, 16) are for setting how many times it renders each frame. The higher numbers are better quality, but if the object isn’t moving too fast you can usually get away with one of the lower ones. Since it is rendering more, the rendertime will be multiplied by whichever number you chose, so use the lower ones when you can.
Did you click on the ‘default’ button in the Display window? That turns on a setup for PAL with Fields. When you convert this to mpeg or divx you get strobing because the fields are being displayed out of order.
Unless you are rendering for video ( as opposed to computer display ) you don’t want fields.
And of course, if you lived here in the states, you would have to set it to NTSC standards, or 30 frames per second if you ever wanted to output to DVD or svcd. And as for the “strobing” effect, I don’t know what exactly you’re talking about, but try rendering to an actual video format instead of individual tga’s. Blender does a pretty good job with compression now that the divx plug is supported for outputing.
I’m trying to do some renders to burn to NTSC DVD. Rendering with fields seems to improve my picture, but it could be that I just really want it to, so that’s what I see. One thing’s for sure though, when I pause the DVD, I get a sort of strobing effect, which doesn’t seem to happen on any of my bought DVDs.
Can anyone help me out? I’m running out of burnable DVDs, and they’re pretty expensive. Thanks!
Yep, tried both even and odd fields. Seems to look best with odd fields (button pressed in), but the pause effect is even more noticeable then.
Maybe it’s the burning software I’m using (Roxio Easy CD & DVD Creator 6, free with the drive) I suspect it doesn’t play nice with raw AVIs. Or maybe it’s the animation itself - blue stripes sliding over a stark white background, lots of motion blur.
THen a little strobing is unavoidable, A frame last 1/25 (or so) of a second. It is rendered as perfectly still but the electrons take 1/25 of a sexond to draw it, so the moving effect should be accounted for.
If you use fields then you take into account thet 1 frame is made by 2 fields, but the assumption that the field are separated by exactly 1/50 (or so) of a second is inaccurate. Indeed each single frame is not perfectly still since it too has a finite drawing time…
I tolk about different frs/sec because of those 2 articles:
http://www.siggraph.
org/education/materials/HyperGraph/animation/cameras/traditional_film_camera_techniqu.htm#Transitions
““Panning and Tilting
For both of these shots the camera is stationary and rotates in a horizontal (panning) or vertical (tilting) plane…
…Inexperienced operators may pan too fast and caused an effect known as strobing. This is also a problem in CG and is called tearing. This can cause motion sickness or cause the illusion of motion to be broken. For example, for an animation at 30 fps, the number of frames needed for a 45 degree pan would be about 22 frames for a quick turn or 66 frames for a casual turn.””
and also: http://www.anticipation.info/texte/lasseter/principles2-1.html
“”"… to help relieve the disturbing effect of strobing that
happens with very fast motion because sequential positions of an object become spaced far apart.
When the action is slow enough, the object’s positions overlap, and the eye smoothes the motionout.
However, as the speed of the action increases, so does the distance between
positions. When the distance becomes far enough that the object does not overlap from frame to
frame, the eye then begins to perceive separate images. Accurate motion blur is the
most realistic solution to this problem of strobing…
So:
motion blur is useful to save us from strobing but to animate a fast and slow action we need to use different frs/sec for every sequence.
example:
a subject walking: 25 fr/sec
running: 50 fr/sec
standing: tga image
Then everything in the sequence editor for a 25frs/sec avi.
Do is correct this way or it 's absolutely crazy? I am doing some experiments with motion blur and differents frs but I still have not interesting results.
There’s another question and maybe it’s what S68 was thalking about:
“”…A problem with this however, is that it takes time to actually draw the screen, so sometimes
OpenGL is only part way through drawing the objects on the screen when it gets told to redraw the
screen, so you see jerky and flickering animation. It is important to realise at this point that OpenGL
does not draw directly to the screen but to a frame buffer, which is then displayed on the screen.
A solution to this problem is to use double buffering…""
Looks like it might be an effect of using overly quick pans. I’ve got plenty of motion blur on it, but my turns are so quick that only the fuzzy edges overlap from frame to frame. Thanks for the advice on pan rates, I’ll try to apply it some in future work.
This has got me thinking, though. How does film (no fields) get transfered to video (with fields). Guess it’s time for a Google search.
I’m not sure how you drew the conclusion from all that that changing framerates is a good idea. The page you linked to agrees with me. Like I said earlier that’s not even possible, if you edit it together to a 25 fps avi, the whole thing will be 25 fps, you can’t change in the middle of an animation.
If you motion blur correctly, strobing should not be a problem anymore. Changing framerates will likely just make everything more confusing.
Teo, one frame of film is shown for 3 fields, then the next frame is shown for 2 fields, then the next frame is shown for 3 fields, then the next is shown for 2 fields, and so on. So you reach the 24th frame of the film at the 60th field in the video.
Computers can only display 30 frames a sec max I think, TV and VCR’s are mostly 60 frames a second but the resolution is so much lower so it can handle all the frames since it only displays 256 colors max.
umm… i dont think so… idk wut computers do, but i believe its more than 30, and tvs… well that depends on where u live. in the USA (NTSC) its 29.997 (how dumb), ni england (aswell as other places)(PAL) its 25. in france (C-CAM) its something else, haha dont remember, but most TVs dont do 60. (some film cameras do, its called overcranking(its used for ‘slo-mo’)(if youve seen matrix reloaded, the scene where the agent, leapfrogs cars, that was shot at 150.))
