- Home /
The question is answered, right answer was accepted
"You should strive to keep mass close to 0.1..." Why?
The documentation in Unity states:
"You should strive to keep mass close to 0.1 and never more than 10. Large masses make physics simulation unstable."
Someone in this thread, used a value of 1500 for a car and seems to work out well. In regards of the docs as quoted above. Why? Why is so significant with "0.1"?
Answer by gfoot · Mar 26, 2014 at 10:22 PM
Large relative mass differences cause problems in some interactions, such as when a light object gets squashed between two heavy objects, or between a heavy object and the ground. The constraint solver ends up needing more iterations to get a good solution, so depending on the implementation it either uses more CPU or it settles for a worse solution in which the collisions are not well-resolved.
For simple cases it's likely to work fine though and I doubt that the absolute value of the mass matters much, it's probably only the ratios between interacting objects' masses that matter. If you do use extreme values, just make sure you test interactions with other objects thoroughly.
Follow this Question
Related Questions
Rigidbodies won't collide if mass difference is too high 0 Answers
Physics.Simulate time increases exponentially relative to rigidbody count 1 Answer
Ways to work around OnCollisionStay/Enter events firing one frame late? 2 Answers
Grow objects 0 Answers
What is the best way to prevent a physics object from going through thin colliders? 2 Answers