2009

■ Usually, increasing the number of substeps on page 4085 in the simulation
improves the stability of the simulation.
■ Also for springs and dashpots, avoid attaching objects with very different
masses. Using a Strength value similar to the mass of the objects attached,
and a Damping value of 1/10th of that Strength usually give good results.
■ If you are using
constraints on page 3925, make sure you have aligned the
constraint spaces on page 3926 properly.
■ If many objects start the simulation too close too each other (inside
collision tolerance on page 4088), reactor will try to push them apart at the
beginning of the simulation. Try increasing the space between them, or
reducing the collision tolerance.
■ If you have constrained two rigid bodies so they are in continuous
contact/penetration (like an upper arm and a forearm), be sure to
disable
collisions
on page 4090 between those bodies.
■ Adding drag action on page 4089 can help damp the overall simulation. Try
increasing the linear drag in the scene.
■ If you are working with Fracture, the
Fracture Tips on page 4017 section
provides information on how to avoid instability.
Cloth/Soft/Rope object stretches too much
If you have attached (using the
Attach to RB Constraint on page 4067) it to a
falling object, be sure to turn off Do Not Affect Rigid Body. If the problem
remains, increase the mass of the Cloth/Soft/Rope, or decrease the mass of
the attached rigid body. Increasing the strength and damping of the
Cloth/Soft/Rope should also improve the situation.
Objects seem to move very slowly
Make sure you are using the proper
World Scale on page 4087 in the scene. A
10cm box falling from a 1m height doesn't behave the same as a 1km box
falling from a height of 10km: The second one will reach the ground much
later). Use real-world units or have a proper mapping between 3ds Max units
and simulation units (
World Scale on page 4087).
Why, after simulation, do I get warnings regarding "topology changes"?
The term “topology” refers to the internal connections of the vertices, edges
and faces of a mesh. If you change the number of vertices in a mesh, you are
4118 | Chapter 16 reactor