Morphing Animation

I have a question about morphing animation. If I were to animate a man picking up a cup of coffee, how to do I keep his arm the same proportions the entire time? If I want to morph things but not use “rubber band” animation what do I do? Is there a trick, or do I just have to morph things and try to keep it looking like it has bones? Are there any tutorials that pertain to this? Thanks for the help.

Currently you have two options:
Use the cut out style technique (see the tutorial section of the wiki)
Use keyframe system and insert as many keyframes as needed to keep the right proportions.

The computer helps on tweening but you have to control the keyframes properly to obtain good results.
Good luck.
-G

Is there a tutorial about the second method which you mentioned? So in an example like this http://www.youtube.com/watch?v=VAtxwFvvuxE does the animator have to move each part and be careful to keep the proportions correct? Or is there a trick to keep the parts intact? Thanks again.

You can also do a combination of both - you make cut out parts (out of blines and regions), then animate the rotations, and then go over it and adjust the vertices to make the joins look seamless
I’ll post something with a couple of examples soon, probly next week

There’s no trick to keeping the proportions, you’ve just got to use your judgement (or you could use photos or videos for reference)

Also remember that the length of a limb is kept during animation only if it rotates in paralell to the camera and would be shortened when pointing to it.
-G

I am also wondering, how do you do something like keep the eyes and nose or your character in the same place on the head when your character is moving around or up and down. Is there a linking way to achieve this or do you just have to use your own judgement? Thanks again for the help!

Lot of people has tried to automate this with more or less result. If you automate it with a math formula you end with a robot. Do you want to have a robot or a character? :mrgreen:

There is not better way to do 3D turns in a 2D program than do it by your self after draw the main poses.
Remember this:

  1. Cartoon characters doesn’t follow the 3D look usually. Mouths are usually drawn not matching the face direction.
  2. In cartoon animations characters don’t do slow head turns. Usually the head turn is made in three phases: prepare, flip, release.
  3. If you need a draw a realistic particular pose (i.e. 3/4) do this:
    3.a) Draw the ‘front’ pose.
    3.b) Draw the head seen form the sky and call it ‘top’ pose. Place this above the front pose. Draw the non visible parts of the face too if any.
    3.c) In the top pose identify the neck axis. It is not centered in the human cranium but and bit back on the neck.
    3.d) Copy the top pose on the right. Rotate the copied by the neck axis the amount you want.
    3.e) Draw the 3/4 pose below the top copied and on the right of the front pose. Use both to match the position of each part of the face and the visibility of things.
  4. Don’t turn heads more than 45 degrees each time. Don’t let the computer to interpolate a 90 degree turn!! 45 degrees is the maximum.

Here is an example of quick cartoon head turn.

viewtopic.php?f=7&t=1088

Hope this helps.

Great information, thanks. How about the eyes on the dog in your profile picture. As the head goes up and down, are the eyes and nose linked to the head, or did you have to judge where they should be in each frame? Thanks again for all your help!

I just draw the first pose and move the head (included the eyes) like a whole between pose and pose. Remember that you can select more than one layer at a time and all the vertices of the selected layers are available to select with the box selection or with the CTRL-left click additive selection.

For this avatar I did first the pose matching to the undelying raster images. Then I fixed the interpolations of the keyframes by modifying the interpolation type or adding additional waypoints when needed. Later I added the secondary movements (ears for example).
Do a walk cycle “in place” is “easy” because you don’t need to translate the whole character across the screen and correct the typical feet sliding between poses. Do a walk cycle across the screen needs more practice.
-G