3 answers · asked · Lesson: Complex Obstacle Drop · Course: Blender Animation Bootcamp

Technically impossible to line up the impact speed without workarounds?


So, I'm working on the exercise with 3 balls. I'm trying to make the bowling ball on the left, and the middle ball reach the ground at the same speed and momentum. However; it is practically impossible to do due to inefficient frame count. Let me explain:

If I make the middle ball the base, and assuming it hits the ground at f15. In F14, based on speed and momentum, the location of both balls would be too high for the left ball to hit the ground. If I make the left ball hit the ground in F15, it  will look like it slows down at the end, and if I make it hit on F14 it will look like it speeds up.

If I make the left ball the base, the middle ball will look like it slows down at the last frame before it hits the ground.

Of Course, I thought of ways to solve this, and I came up with a few (in no particular order):

#1. Change the X axis of the left ball. move it to the left, to make the ground meet the location where both balls should be on F14.

#2. Make the balls drop from various heights.

#3. Increase the number of frames.

#4. lower the height from which they drop, so they don't get too much momentum, and make their drop speed easier to deal with.

I'll simply tweak the left ball to the left, or change the height of the plane from which it bounces, but I wanted to address this. Maybe oh .. I don't know ... blender has a way around this ? Maybe I can tweak the graph editor within half of a frame :P (Technically impossible and practical, since said frame won't show anyway!)

I also would like to ask, would I have to change some of my initial choices to work around limitations like these in the future? (not necessarily in this course, but in general)

  • crew

    Ahhh, you're starting to see problems and solve problems.  Good.  That's a lot of what animation is.

    This is one of the situations where you have to "cheat it".  Which we can do in animation.  First base it on reality, (or a tweaked version of reality) and then cheat things to make it look "better than real life".

    So to solve this issue you need to decide what the best thing to do is.

    Do you cheat the bowling ball or do you cheat the middle ball?

    That depends on the situation.  You can adjust the positions and/or the height to lessen any cheating but ultimately you will need to play around with a few of the solutions you have mentioned and then decide which one works best.

    Are you starting to day dream about animation yet?  (My guess is yes!  Welcome to the club haha)