Softimage XSI

Turbulize the position of a locator with ICE kinematics

Controlling the scale, transformation or rotation (SRT) of an object with ICE isn’t any different from doing the same when dealing with point or “particles”. The thing you need to keep in mind though is how you set the data. While you can read any of the SRT properties of an object you can’t set the individual X,Y or Z transforms directly nor their local transform values. In order to set any of the transform values you need to set the whole global transform matrix. Note that this is merely a structural thing and does not affect what you can and cannot do with an object’s SRT. 
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Particle sprites using ICE

Sprites are images or sequences of images which you map onto a surface, usually with an alpha channel, to create the illusion of a three-dimensional object or volume. Typical use of sprites includes populating trees with thousands of leafs or creating fire and smoke effects, as this is much more cost effective than rendering  instances of the actual objects or using volume clouds. And in most situations you wouldn’t be able to spot the difference anyway.
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Squash and stretch

One of the most fundamental (and important) rules in animation is the use of squash and stretch which is used to give the illusion of weight and volume as an object moves.

Open the scene Ball_Rig.scn. Select the Ball and from the Get > Primitive menu choose Lattice. In the Lattice PPG, change the Subdivision on all three axis’s to 2 and close the PPG. With the Lattice still selected, press [T] to set the selection filter to points and select the top nine points on the lattice. From the Main Command Panel (MCP) > Edit menu choose Create Cluster with Centre. This creates a null object and automatically constrains the selected points to that null, meaning that if you move (or scale) the null the corresponding part of the lattice will move as well.

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Surface constraint and transformation

While constraining an object to a surface as such is a straightforward task and won’t require more than a few mouse clicks, it may still leave you with a sensation of not being quite satisfied. Once you add the constraint you loose the option to freely move the object with the standard translate tool and are left with two (somewhat less intuitive) sliders within a PPG. By adding an extra dummy object to the mix, you’ll effectively manage to get the most out of both approaches.

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Frame number as 3D text

From the Create > Text menu choose Solid Mesh. Unlike most other parameters in Softimage, the editing pane does not come with an animation icon and as such it does not offer a direct way to animate or control via expression. However, this certainly does not mean it can’t be done. You’ll return to the PPG in a second, but close it for now. There’s a slight difference between the standard primitives in Softimage and the text object. While the standard primitives creates a single object the text operator instantly renders your input text as curves which are then converted to a 3d object using the convert curves to mesh command.

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ICE destruction

Whether it’s alien lasers, judgment day prophecies or just that really cool thingy that will self-destruct messages in five seconds, having a tool that can turn an object into dust for whatever reason can certainly become handy in the VFX demanding times of today. Anyone who has ever worked on a VFX shot knows that the second you start relaying on key framing the effect by hand the chances of the director all of a sudden changing his mind and want it to go in another direction is one hundred percent. And that is if we’re being optimistic. So the goal is to design a tool that is flexible enough to change the object getting disintegrated and the factor setting of the effect without relying on you manually setting keyframes.

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Create dimples when particles collide with the surface

Just a few years ago (or versions of Softimage if you will) this type of effect would require a fair amount of time and patience and certainly wasn’t something you would whisk together in three little steps. By using ICE there’s actually very little information you need to extract from the scene in order to create the dimples. You obviously need to find the whereabouts of the particles and the points on the geometry you want to dent but that’s about it.
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Procedural orange skin

There’s a vast variety of oranges and citrus fruits, each with their distinguished color, shape and texture. But they can all be created using the same basic set of nodes.Open the scene orange.scn, select the Orange and press [7] to open a Render Tree. From the Nodes > Texture menu get a Cell Scalar node and open its PPG. Many of the changes made to the nodes are subtle and may be hard to see solely relying on the shaderball. To get a better view of how the values affect the output you can temporary connect the current node directly to the Surface input of material node and draw a render region in the viewport.

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Using individual textures in shared materials

The reason you apply the same material on multiple objects in the first place is usually because you want them to be exactly the same. That’s pretty much the definition of sharing the very same material. With that being said, let’s discuss how you can setup a shared material but still being able to control parts of it on a per object basis. While this answer confines to using an individual texture, there’s nothing stopping you from adding additional individuality. But then again, if you really want completely different appearance for each and every object you’re probably better of using separate materials in the first place. 

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How to offset point position in ICE

Start a fresh scene and from the Get > Primitive > Polygon Mesh menu choose icosahedron (any dummy object will do) and set the Geodesic Frequency to 4 to make it a bit smoother. With the icosahedron still selected, press [4] to switch to the Simulate toolbar and from the ICE > Create menu choose Emit Particles from Selection. With the pointcloud selected, press [Alt]+[9] to open an ICE Tree.

Open the Emit from Surface PPG and change the Rate type from Number of Particle per Second to Total Number of Particles and Size to 0.5 or so. By default, the shapes of the points are set to (which may not be totally unexpected) just points. While this is sufficient to determine their position, there’s no way to tell their size or in which direction they’re oriented. So for clarity, change the Shape to Cone. In the Orientation section of the PPG, check the Align to Surface Normal checkbox.

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