Particle Flow Smoke


This is a simple particle age smoke to get us started using Particle Flow.



Our birth has 2,000 particles for a fast render, but we could easily use 10 times that amount.



Speed is on the slow side



Forces are wind to provide direction and drag to slow down particles as they rise


Our wind is responsible for moving the particles



The drag is set to slow down particle motion by a percentage as it goes along the Z axis, based on the drag icon’s local Z.



The Shape facing operator is critical ... we have to assign a camera viewport ... and, we also need to allow spinning in the orientation ... this is so we can rotate the facing materials as they move. Finally, we can also apply the size here.



Material operators come in three varieties: Static, Dynamic, and Frequency. Static is pretty straightforward, assigning materials and IDs that don't change during an event. Dynamic, on the other hand, lets particles' material IDs change during the event, and supports animated materials using Particle Age and similar maps. Frequency works directly with sub-materials. You create a list of materials and weight their assignments to particles based on percentages.



We will use the material dynamic operator so we can use particle age for our smoke. Here is the setting:



Next is the spin operator, which works like spin time in non-event particle systems like super spray. Remember, we had to select allow spinning in shape facing. Now we have to specify particle space so the particles keep facing us.


The spin rate is in degrees per second. The variation is number of degrees per second we can vary. Divergence is set to the max of 180. At 0, all particles would spin together, looking completely uniform.



Display ...



Finally, Delete is set to simply kill off particles when they are 90 frames “old.”