A strong conscious effort has been made on my part to ensure that the interface to my N-body gravitational simulator is as intuitive and versatile as possible. The following is a step by step outline of the procedure one would use to set up the initial conditions for an N-body simulation run.


Step1: Setting a Location

The first step in setting up a simulation is specifying a center location for a cluster of particles. This is done by a simple click of the 3D cursor shown above. The user may change his or her vantage point via the navigational window shown in the lower right corner. There are several viewpoint movement modes to choose from.


Step 2: Defining an Outer Bounding Box

In this step the user determines the XYZ dimensions of the cluster. The bounding box is used to specify the axial values for the ellipsoid form of the final cluster.


Step 3: Defining an Inner Bounding Box

This feature allows the user to create shells, or hollow centers for the clusters.


Step 4: Set The Bounding Box Orientation

A great deal of time has been spent to provide an intuitive method of allowing the user to orient a cluster in 3D space. All rotations are performed in view coordinates about an axis specified by mouse movement.


Step 5: Set The Velocity Vector

This step calls for the user to specify a net velocity vector for the cluster. In this way, the user can set up collision situations between clusters.


Step 6: Specify Additional Parameters

Here, additional parameters are specified through the use of a dialog box. These extra parameters concern number of particles, radial velocity, mass bounds, and spatial and mass distributions.


Step 7: Option to Create Multiple Clusters

The user is given the option to repeat the setup process for another cluster if desired. In this way, interesting collisions scenarios may be simulated. Also, the current cluster is generated and appears within its bounding box. In this image the particles are difficult to se due to image reduction for the web page.


Multiple Clusters