- You'll need to plug your emitter geometry into a Fluid Source node. You might want to turn off empty interior. As always, label with a null. OUT_SOURCE. Add a scalar volume and label it temperature. Your pyro won't react properly to buoyancy otherwise. THANKS HOUDINI.
- It's a good idea to create two bounding boxes - one for the source, one for the padding. Make the padding way bigger than the source, freeze the time so it doesn't jump around in the simulation. You don't have to freeze the source bounding box as the solver only takes the first frame anyway. Label them with nulls, with something like OUT_BOUND and OUT_PAD.
- Inside a dopnetwork -
- You need a Source Volume node. use your OUT_SOURCE as your volume path. Initialise it to Source Smoke. Set the Velocity to Add. Otherwise it will just keep overriding the velocity.
- You need a Smoke object. You might as well link the Division Size to the same parameter in the Fluid Source you created earlier. For the size and centre parameter boxes, use these respective expressions with the relevant paths and axis variations -
centroid("../../geo1/OUT_BOUND",D_X)
- In the Creation tab, you'll probably want to tick ON Solve on Creation Frame. This gives the system some density on frame 1, so it won't immediately shrink and implode on itself.
- Next you need a Gas Resize Fluid Dynamic node. This just keeps track of the size of the simulation. Tick ON Clamp To Maximum, set it to From Object and point it toward OUT_PAD. Nice and easy, no expressions required. You still might have to faff with the padding values in the Bounds tab....
- Lastly, but not least - you need a Pyro Solver node. Plug the Smoke Object into the first input, the resize into the second and the Source Volume into the last.
That should all work! The Solver contains most of the turbulence/shaping controls for the simulation.
You now have a basic pyro setup without using shelf tools. YAY.
