Making It Wobbly

Introduction to reactor

Simulation Accuracy

 

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

Looking at Things Differently

reactor allows you to use display proxies for objects; this means that a rigid body can have a different display body for use in the preview window. This improves the window's performance, especially when you are simulating more than one object with the same display body. If you have a lot of objects that all look the same, then your display only needs to keep track of one instance of the display body when display proxies are used. As a bonus, you increase simulation setup speed, because you create only one instance of the display body.

In this lesson you'll create a display proxy for the toy. This is so that when you create copies of the toy later in the tutorial, your setup and display speed won't be adversely affected.

Continue using the scene from the previous lesson, or open reactor_intro_7.max from \tutorials\reactor\introduction.

Create a display proxy for a rigid body:

1. Create a copy of the toy by Shift+dragging the group in the viewport.

   Move the copy away from the other objects.

2. A display proxy must be a single mesh. To create this, first ungroup the toy copy by selecting the new group and choosing Group menu > Ungroup. Then select the copy's main body sphere.
3. Right-click the sphere. In the Transform quadrant of the quad menu, choose Convert To > Convert To Editable Mesh.
4. In the Edit Geometry rollout of the Modify panel, click Attach List.
5. Use the Attach List dialog to select the rest of the objects that were part of the group, and then click Attach.

   You now have a single mesh representing the toy that you can use as a display proxy.

   TipIt is a good idea to label models in your scene clearly, especially when they look similar to one another. In this tutorial, for example, you could rename your proxy object toy_body_proxy .
6. Select your original toy_body group and choose Group menu > Open.
7. Select the group parent, which is the pink box surrounding the grouped objects.

   You need to select the group parent rather than any of the toy's constituent objects, because the group parent represents the rigid body and display proxies are applied to rigid bodies, not primitives.

8. Open the Rigid Body Properties dialog, and on the Display rollout, turn on Proxy.

   This activates the display proxy pick button.

9. Click the display proxy pick button and select the single-mesh version of your toy in one of the viewports.

   

   The button displays the name of your proxy object, in this case toy_body_proxy.

   You have now assigned an alternative display body to your compound rigid body.

10. Hide the proxy object: Select the single-mesh toy, right-click, and from the Display quadrant of the quad menu choose Hide Selection.

    This will keep it out of your way.

11. Select a component of the group, and choose Group menu > Close, then click Preview Animation.

    Your toy will use the new mesh as its display object. If you make changes to the editable mesh, these will be displayed whenever you use the preview window.