Getting Collective

Introduction to reactor

Geometry Types

 

Autodesk 3ds Max Tutorials > Special Effects > Introduction to reactor > 

The Basics of Simulation

Now that you have a valid scene for simulation, you can try simulating it. reactor provides two methods for simulating animation:

• The reactor preview window displays your simulation using OpenGL or DirectX. You can examine your objects’ physical behavior in the window, see how they interact, and even use the mouse to interact with the scene. You can use this window to update the rigid bodies’ states in 3ds Max at any time during simulation, which means that it acts as an interactive scene modeler.
• Alternatively, use keyframe creation. You define an animation range, and reactor creates and simulates the physical world across that range, passing the rigid bodies’ states back to 3ds Max as keyframes.

Continue using your scene from the previous lesson, or open reactor_intro_2.max from tutorials\reactor\introduction.

Examine your scene in the preview window:

1. Go to the Utilities panel, click the reactor button, and, on the About rollout, make sure Choose Solver is set to Havok 1.
2. On the reactor toolbar, click Preview Animation.

   This opens your scene in a preview window. By default, your scene is initially displayed from the Perspective view. You can use the left mouse button to rotate the camera, the middle button to pan, and the scroll wheel to zoom.

3. To start your simulation, open the Simulation menu in the preview window and choose Play/Pause, or press P on your keyboard. Your simulation start and the sphere will fall onto the box.

   You can use your right mouse button to drag the sphere around the scene. However, you cannot move the box, because it has no mass.

   TipTo reset the simulation, press R.
4. When you’re finished exploring your simulation, return to 3ds Max by closing the preview window.

Create physically-based keyframes:

Next, you will create keyframes for the objects’ interaction. A sphere falling onto a level surface isn't very interesting, so first you will tilt the box so the sphere will roll along its surface.

1. In the Left viewport, select the box and rotate it clockwise about 30 degrees, being careful not to let it touch the sphere.

   

2. On the reactor toolbar, click Create Animation. A Reactor dialog appears, asking you to confirm the choice. Click OK to continue.

   This creates a simulation and runs it for the length of time between the Start Frame and End Frame values set on the track bar. The default values for these are 0 and 100, respectively; you will change these values later in the tutorial.

   reactor creates keyframes for the positions and orientations of your rigid bodies for each of those 100 frames.

3. Click Play Animation to watch the animation in the viewport. You should see your sphere falling onto the box and rolling down over the edge of it.
4. At frame 0, select the sphere if necessary, and then Alt+right-click the sphere and, from the quad menu > Set quad, choose Delete Selected Animation.

   The sphere's keys on the track bar go away.