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Newton's cradle (also known as Newton's balls) is a device to shows the law of conservation of momentum and energy via a series of swinging spheres. Newton's cradle consists of an odd number of identically sized metal spheres (usually 5 spheres) and they are just touching each other at rest. Each sphere is carefully aligned along horizontal lines by two wires that are equal in length and angle. When one sphere on the end is lifted and released, the resulting force travels through the line and pushes the last one upward. In this tutorial I want to show you how to simulate this effect by reactor in 3D Studio Max.

By hani, on October 01, 2010, under 3D Studio Max Tutorials
 

Newton's cradle (also known as Newton's balls) is a device to shows the law of conservation of momentum and energy via a series of swinging spheres.

Newton's cradle consists of an odd number of identically sized metal spheres (usually 5 spheres) and they are just touching each other at rest. Each sphere is carefully aligned along horizontal lines by two wires that are equal in length and angle.

When one sphere on the end is lifted and released, the resulting force travels through the line and pushes the last one upward.

In this tutorial I want to show you how to simulate this effect by reactor in 3D Studio Max.

 
 

Final Result Preview:

 
 
 

Introduction:

 

Before starting I want introduce my scene and relationship between objects.

  • No.1- There are 5 spheres with red color as Newton's cradle's ball.
  • No.2- Wires
  • No.3- Tubes
  • No.4- Cylinders

Tubes are linked to Spheres. So when Sphere moves, its Tube also follows it. Each wire is connected to its Tube by Linked XForm modifier.

 
 

Step 1:

 

Select all Spheres and Cylinders then click on Create Rigid Body Collection on the Reactor bar. In this way, all selected objects will add to RBCollection. if not, simply add a RBCollection in scene then in its parameters hit Add button and choose all Cylinders and Spheres.

 
 

Step 2:

 

Next you need to modify the Sphere properties. Select all Spheres and click on Property Editor. Change the parameters same as below picture.

Mass is weight of object. You can try the values among 10 to 20 and see result. But be careful about Elasticity. If it be low, the spheres will move hardly.

 
 

Step 3:

 

In Top view create a Point - Point Constraint for wires. Each Sphere needs two Point - Point Constraint and their position is not important.

 
 

Step 4:

 

Select the first Point - Point Constraint. Go to modify panel and check Parent. Here Cylinder is parent and Sphere is child. Click on Parent button and then select its Cylinder (the Cylinder that wire is connected to that). Then click on Child button and choose its Sphere from scene.

Now select the Stiff Spring from Constraint type group and click on Each Body button.

First wire is ready. Now repeat Step 4 for connecting other Point-Point Constraints.

 
 

Step 5:

 

Our Constraint will not work without a Constraint Solver. So in next step we need create a Csolver.

On the Reactor bar, choose Create Constraint Solver and click on the scene so a CSolver will be creating there. On the Csolver parameters hit None and then choose RB Collection which before created in scene.

Now hit Add button and select all Point-Point Constraints in scene. Also make sure Deactivation Threshold is sets to 0.0.

 
 

Step 6:

 

Simulation is ready. You can hit Create Animation on the Reactor bar to create animation or choose Preview Animation to watch realtime