Block Actors
Virtualwind provides tools to visualize the effects of the wind resolution (dividing the Domain into the specified numbers of cages in X, Y, and Z directions respectively) and the Domain settings (Domain size, position, and orientation) on structural entities, such as Buildings, Canopies, Smokebombs, and Terrain. By creating the so called Block Actor for a particular entity, you can get a rough idea as to how the Virtualwind flow solver recognizes this entity when it is solving the simulation.
To create a Block Actor, right mouse click on the entity in the entity tree and choose Create Block Actor from the pop-up menu. Below is the example of the Block Actor (shown in wireframe) created for the skybridge connecting the two towers in the simulation for the Petronas Twin Towers. As you can see, what the flow solver "sees" are mainly blocks. The wind resolution and Domain size determine the sizes of those blocks. The smaller those blocks are, the closer they approximate the real shape of the structure. Once a Block Actor is created, a new Actor item, named Block Resolution by default, will be added to the entity tree under the particular entity. Similar to all the other Actor items, by modifying its properties you can control its appearance in the viewport.
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When you change the wind resolution or the size, position, or orientation of the Domain, the sizes and/or the positions of those blocks will change as well. Therefore, what is rendering in the viewport may become outdated. In this case, Virtualwind automatically turns the outdated rendering of Block Actors into red to remind you that what you see now does not reflect the current state of the wind resolution and Domain settings. You can use the pop-up menu, as shown below, to control the way you want to update the particular Block Actor.
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You can manually update the Block Actors by choosing Update Block Actor from the pop-up menus. Alternatively, you can choose Continuous Update to turn on the continuous update mode, in which Virtualwind automatically updates this Block Actor whenever it becomes outdated. Once the Block Actor is updated, its color will be turned back to white (the non-editable default color) again. To exit the continuous update mode, simply choose Continuous Update again.
This tool is useful when you trying to determine a proper wind resolution for your simulation, particularly if there are fine features in the geometry that you want to make sure they are "seen" by the solver. However, be aware that, with the wind resolution getting finer and finer, the time and memory costs on executing the simulation quickly increases and eventually they may become unacceptable.