Moving from Legacy Particles to ICE Particles

As of Softimage 2011, the legacy particle operators (ParticlesOp, ExplosionOp, and FluidOp) and their shaders are no longer supported (Particle Billboard, Particle Blob, Particle Color, Explosion, Particle Gradient, Particle Renderer, Particle Scalar, Particle Shape, Particle Sphere, Particle Sprite, and Particle Vector shaders).

This means that you can no longer load scenes that contains the legacy particles into Softimage 2011. Sorry, but you knew this day would come!

Sooooo ... if you’re used to working with the legacy particles that were available in previous versions of Softimage, you've got some transitioning to do! You’re going to recognize some concepts and features from the legacy particles with ICE particles, but that’s where it ends.

Everything for ICE particles works in a completely different system.

ICE is a visual programming environment designed to allow you to easily create particle effects, and more. The ICE tree is a powerful paradigm that gives you direct access to elements inside the code.

You may find the learning curve for using the ICE tree a little steep at first, depending on what you want to do and what your technical level is, but soon you’ll find yourself connecting nodes together like a pro!

Make sure to start out with the example in Making Fire with ICE: A Particle Walkthrough. After that, you should dive into the rest of the ICE Particle sections in the user guide, and check out the sample ICE scenes that are installed with Softimage.

This table gives you a quick summary to help you transition your thinking from the legacy particle system to ICE particles.

Legacy Particles ICE Particles
Particle cloud Point Cloud — see ICE Particles Are Points (
Particle operator Simulate Particles node — see Creating ICE Particle Emissions (
Particle emission Emit compounds. You can emit particles automatically when you choose ICE > Create > Emit Particles from Selection on the Simulate toolbar.

See Creating ICE Particle Emissions (

Particle type (ptype) Not applicable. Points are included in a point cloud and you define their properties with attributes. Many attributes are exposed in compounds, such as the Emit compounds.
Particle shaders There are special particle volume, density, fractal, and gradient shaders, as well as several particle shader compounds in the render tree. You can also use any type of shader on particles since they are seen as standard geometry to the mental ray renderer.

See ICE Particle Shading (

Max Life/Age limit Set Particle Age Limit compound. If you don’t define an age limit (and delete the particles at their age limit), particles live forever — see ICE Particle Lifespan (
Forces You can use the forces from the Get > Force menu on the Simulate toolbar, then bring it into the ICE tree and plug it the Add Forces compound. There are also many ICE forces that you can use in the ICE tree—they don’t create a control object in the scene.

See ICE Forces (

Collisions Two different ways:
  • Use the Simulate Rigid Bodies node to make particles into PhysX rigid bodies (like regular non-ICE rigid bodies). This allows for interparticle collisions, and collisions with other obstacles. See ICE Rigid Bodies (


  • Use the different Surface Interaction compounds, such as Bounce Off Surface, Slide on Surface, and Stick to Surface to have the particles interact with other objects, but not as rigid bodies. See Motion Control and Surface Interaction Behavior for ICE Particles (
Goals Goal compounds—see ICE Particle Goals (
Particle events State compounds: Actions (state effects) like bounce, slide, stick, etc. happen when a Trigger (like every nth frame, particle age, collision, etc.) reaches its value. Plug State nodes into the State Machine compound, then define each State as you like.

See ICE Particle States (

Particle trails Two types of trails:
  • Spawning compounds emit new points - see Spawning ICE Particles (


  • Strand compounds leave trails behind the particle - see ICE Particle Strands (
Instances Geometry Instancing compounds — see ICE Particle Instances (Objects as Particle Shapes) (
Noise Turbulize compounds — see Turbulizing Particle Values (
Random values Randomize compounds — see Randomizing Particle Values (
Particle Orientation Orientation compounds — see ICE Particle Orientation (
Static clouds Create unsimulated point clouds - See Working with Unsimulated Point Clouds (
Deforming particle systems You can do it best with unsimulated point clouds, but you can deform simulated particles too by using the Post Simulation region of the construction history. See Working with Unsimulated Point Clouds (
Explosions Use the Spray from Controller and Emit Blast compounds for the right movement.

See ICE Particle Orientation ( and Creating ICE Particle Emissions (

Fluids Use the Blob compound to blend particle blobs together — see ICE Particle Blobs (
Simulation time and playback You can play back the particles as usual using the playback controls in the timeline. Use the Simulation Time Control property editor to control how the particles are played, the same as is used for non-ICE rigid bodies. See Playing an ICE Simulation (
Initial states Choose ICE > Edit > Set Initial State on the Simulate toolbar. See Creating an Initial State for ICE Simulations (
Caching/ptp files No more .ptp files! There are three ways to cache ICE particles:
  • Use the Cache Manager (choose Tools > Plot > Cache Manager on the Animate toolbar) to create a point cache file.


  • Use the Cache on File node to read and write cache files in the ICE tree.


  • Use the Simulation Time Control to cache files, the same way as rigid body caching, and use them in the mixer.

See Caching ICE Simulations (

Importing/exporting particle systems Save all particle system elements (emitter, point cloud, forces, obstacles, etc.) in a model and then import or export it.

You can also save an ICE particle effect (the point cloud’s ICE tree) within a compound and then export that to be used on any other ICE particle system.

This page was last modified 20:19, 9 Dec 2010.
This page has been accessed 16860 times.

© Copyright 2009 Autodesk Inc. All Rights Reserved. Privacy Policy | Legal Notices and Trademarks | Report Piracy