Monday, July 23, 2012

Tool for Automated Dust Trails

I've got permission from RTT to present some of the tools i wrote for them over the last years. I'm not allowed to supply any script files for download but i can show their UI and functionality.

This one is called "Automated Dust Trails". Its a nParticle based dust trail tool that was optimized to work with RTT's car rig. I wrote the tool in 2009 when we prepared for the Lotus Elan spot, but it was used in many other productions since then.
The system uses dynamic hair follicles to read the speed of each wheel. The speed influences emission rates and density of particles. All relevant parameters (color, size, lifespan, density/opacity, emitter attributes, shading, etc.) are adjustable through a convenient UI, so even other operators with little to no experience in dynamics can generate dust trails easily.

Language: MEL 
Size: ~6500 lines (incl. UI)

Main features:
  • automatic detection of RTT car-rigs
  • automatic dust trail creation for any number of cars
  • wheel velocity drives nParticle density & emission rate
  • closestPointOnMesh / closestPointOnSurface nodes and in some cases colorAtPoint expressions are used for terrain specific dust trail options (e.g. to get the trail color from the terrain texture)
  • use of a volumeNoise on the blobMesh channel of the particleCloudShader is based on a technique described in detail on djx blog, but goes further by controlling more shader attributes on a per-particle basis
  • load and save presets option in menu
  • all relevant attributes adjustable through a custom UI
  • only few expressions, most of it is node-based to optimize performance

 (click to enlarge)


  1. Why is not public... so, sell it!

    1. hey saito,
      glad you like it! :)
      actually i would love to make it public. but the tool belongs to the company i work for (RTT AG), since they payed me to write it. ;)
      also, the tool is tailored for rtt's pipeline and car rig. so to make it usable for other people i would have to change it quite a bit. anyways, i might do a private rewrite for general use (with new techniques and fluid support) if i find the time ...

  2. Thanks for sharing some info about the tool! Very interesting to see!

    1. You're welcome! Glad you like it. :) Actually it got a bit long in the tooth by now. I really should think about a python rewrite with additional fluid options ...