Car dust trail in animation with quick effect smoke, problem dust dies after first frames

[Prettypicturegirl]

Hi,

I have a car on a dirt track.
Created a domain around it which entails the complete piece of track as I need the dust to below out over a long distance.
Domain is set to Gas, 64 div, Time 1, CFL 4, Adaptiv Time Steps On,4,1 Delete in obstacle
Dissolve On, 10 Slow

Car body is collision effector.

Wheels are: Type: Flow, Flow type: Smoke, Flow behaviour: Geometry, Initial temperature: 1, Density: 1
Surface emission: 0.5 fwd, 2 aft, Initial velocity:1

When I run the animation I have a lot of smoke in the first few frames and start location, but the tires seem to stop emitting more smoke/dust when the car is moving forward.

All done in Cycles 2.92, Car rigged with Car-Rig-Pro (Can’t share file because of this paid rig). Any thoughts why my wheels do not contiue emitting dust?

Thanks for your help.

[DNorman]

Hi, I had a similar problem with my traction engine, I wanted the smoke to follow the engine around a long track and go around the curves leaving trail of smoke. Smoke had lots of problems I could not find away around.
In the end I opted for a particle system instead of real smoke. I made a cube with volumetrics and a similar node setup as if it was a cloud (sphere gradient for density with noise texture etc) to use for the particles. As it is a particle system you have a lot of control over the effect and you are not limited to a domain (and its resolution etc). The actual particles I used are quite large in size, I did adjust their size and rotation over their lifetime.
Here is a link to the tread with an animation of the smoke.

Traction Engine

I have finally added the differential effect to the wheels. At first I tried to use the rotation of the main drive control bones as a factor for my rotation driver, but that only worked going into the turn, coming out it would revers the desired effect! In the end I placed two new bones perpendicular to the chassis bone (for the back wheels) and the front wheel direction bone (for the front wheels). The z rotation of those bone does work. Now it will react to all the turns automatically along t…

Maybe this approach could be useful.

[Prettypicturegirl]

Thank you. I’ll give that a shot. Btw. your traction engine animation is fabulous.

[DNorman]

Thank you for the compliment.
I based my particle system on this video: https://www.youtube.com/watch?v=tL0G5oOjdtk
but instead of planes I used a cube with volumetrics.
The advantages I found with particles where:
They will linger around where they where emitted for as long as the lifetime you give them and you can control how fast they rise painlessly.
You can move the emitter with your vehicle and the particles will naturally leave a trail,
there is no need for a wind force field to make them go backwards behind the vehicle, you can also give them a random movement with the brownian setting and do not need turbulence.
They are not limited to a domain and will render much faster than a huge domain with tons of resolution.
The simulation is much faster then a smoke sim!

The video example is a very small portion of the track I made, the simulation will go on for miles!