Tracer Particle Generator*
Definition
A Tracer Particle Generator is an imaginary object (i.e., it does not interfere with the air flow) that can release massless particles at a certain frequency for a certain period of time. It is provided as a useful tool to visualize the air flow. In the viewport of Virtualwind, the shape of Tracer Particle Generators appears as the following:
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Creation and Deletion
Similar to Smokebombs, you can create Tracer Particle Generators in Virtualwind via the Entities → Tracer Particle Generators → Create Tracer Particle Generator sub-menu item as shown below. You can delete a Tracer Particle Generator by right-clicking on the particular Tracer Particle Generator in the entity tree and choosing Destroy Tracer Particle Generator.
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Model Settings
Virtualwind allows you to specify the position of the Tracer Particle Generator, the color of the particles that it releases, the particle generation mode, and whether or not you want it to be present in the simulation. The particle generation mode specifies whether to release a particle once or to continuously release particles for a certain period of time. If you choose to release the particle once, you need to specify the release time. If you choose the continuous mode, you need to specify the frequency and both the start and end time for releasing particles. All these can be set up in the Model item of the Tracer Particle Generator in the entity tree as shown below.
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Note that the position of the Tracer Particle Generator is specified with respect to the world coordinate system – the same one that defines the Buildings, Canopies, Terrain, etc.
As shown in the above figure, whenever you create a Tracer Particle Generator Virtualwind will attach a Monitor, the Tracer Particle Monitor, to it to sample the necessary air flow and particle data during the execution of the simulation for future visualization purposes – remember that the creation of Tracer Particle Generators is mainly for visualizing the air flow. Settings for this Monitor can be found and modified in the Monitors item of the particular Tracer Particle Generator. Refer to the Tracer Particle Monitor section for a detailed explanation of this monitor.
Actor Settings
The Actor item contains the settings for the appearance of the Tracer Particle Generator from which you can do the following:
- show or hide the particular Tracer Particle Generator in the viewport by checking on or off the View Status check box;
- show or hide the shading representation of the Tracer Particle Generator in the viewport by checking on or off the Shade check box;
- change its color by clicking on the Color box;
- show or hide the wireframe representation of the Tracer Particle Generator in the viewport by checking on or off the Wireframe check box;
- change its transparency by changing the number of X-Ray Intensity in the range of [0, 1]**;
- change the size of the actor by changing the number of Size.
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