Tutorial 5: Start from Scratch - Part 3

In this tutorial, you set up a position Node and add some dynamics like gravity.

In the last tutorial you created some particles and gave them motion, size, shape, and position. Now you will modify the position to use an object in the scene that you can move by hand or link, and you’ll also add a dynamic force such as gravity.

• Start up 3ds Max and open the file Tutorial4Part2Start.max from your C:\Documents and Settings\All Users\Documents\cebas\Sample Scenes Shared\thinkingParticles\Tutorials folder. 

This is the scene with a Particle Age Condition controlling the Position operator. The first step is to add a Node Helper to base the particles’ position on.

• Create a Dummy object in the Perspective viewport with Create > Helpers > Dummy. Name the dummy PositionNode.

• Open the thinkingParticles dialog by using the shortcut keys Alt+Shift+P.

• Select the Pos_Size_Shape DynamicSet.

• Click the Helpers icon and add a Node helper to the Pos_Size_Shape DynamicSet.

• With the Node Helper selected, from the rollout, click the PickNode button then click on the PositionNode dummy object in the scene.

This sets the dummy object as a node that can interact with thinkingParticles. Now you'll hook it into the DynamicSet.

• Connect the Position output data stream of the Node helper to the Position input data stream of the Position operator.

This sends the position information from the Node helper to the Position operator and finally to the Particles group. Now you can move, animate, and link the dummy in the scene and the particles will follow.



The Node Helper piping position data into the Position operator


Now it’s time to set up some forces. You will set up wind and gravity to act on the particles.

• Close the thinkingParticles dialog using the Alt+Shift+C hotkey.

• Go to Create > Space Warps > Forces in the 3ds Max command panel.

• Create a Gravity space warp in the Top viewport, and set its Strength to 3 in the Modify panel.

• Next, create a Wind space warp in the Left viewport.

• Select each of these space warps and bind them to thinkingParticles particle system using the Bind to Space Warp button on the main toolbar.

It is critical that you set up your space warps and bind them to the TP icon in the 3ds Max viewports before you add them within the thinkingParticles dialog, or you will not see them in the list of available forces.

• Open up the thinkingParticles dialog again using the Alt+Shift+P hotkey and create a new DynamicSet named Force.

The new Force DynamicSet in the Tree View

1. Click on the Groups icon and add a Particles group to the Force DynamicSet.

2. Next, click on the Operators icon and select Dynamics from the dropdown list.

3. From the dynamics list, click on StdForce and add this operator to the Force DynamicSet.

4. Connect the Particle input data stream of the StdForce operator to the Particle output data stream within the Particles group.

In the Inactive List are the 2 space warp forces you bound to the particle system earlier.

• One at a time, select both the Wind01 and Gravity01 from the list, then click Activate.

Both space warps move into the Active list and will have an impact on the particles.

• Press Play to see the particles being affected by the forces.

Particles being effected by wind and gravity in the Perspective viewport

• Save your scene as Tutorial5Part3.max.