Setting the nParticle Sparks attributes

To make the particles behave more like sparks, they need to have a limited lifespan, and they cannot self-collide. To simulate the streaking effect of fast moving sparks, you change the particle render type to Tube (s/w). Note that this streaking effect is only visible after rendering a frame.

1. In the Outliner, select the nParticle_sparks object, then click the nParticle_sparksShape tab in the Attribute Editor.
2. In the Lifespan section, set the following:
   • Lifespan Mode: Random range
   • Lifespan Random: 6

     Increasing Lifespan Random makes the particle lifespan more random, like real sparks. Randomizing the spark lifespan decreases the number of sparks that are visible in the scene at any one time, making the spark effect less dense. To compensate for the random lifespans, you will increase the nParticle emission rate later.

3. In the Dynamic Properties section, turn on Ignore Solver Gravity.

   Later in the tutorial, you add an external Gravity field to control the behavior of the sparks. If the Nucleus gravity is also affecting the behavior of the sparks, the external Gravity field will not have the desired effect.

4. In the Shading section, set the following:
   • Particle Render Type: Tube (s/w)

     This type works well for simulating sparks, since you can control streaking effects using the Tail Size and Opacity attributes.

   • Threshold: 0

     This makes the sparks display individually with no surface blending.

   • Radius 0: 0.08
   • Radius 1: 0.08

     This sets the radius for the tube at its starting point and at its ending point. For this effect, the sparks have the same radius at their starting and end point.

   • Tail Size: 1.25

     This scales the length of the tail, controlling the length of the streaking effect.

   • Opacity: 0.27
   

   For more information about Tube (s/w) type particles, see Particle nodes in the Dynamics guide of the Maya Help.

5. To increase the number of flying sparks, in the Attribute Editor, click the emitter_sparks tab, and in the Basic Emitter Attributes, set Rate (Particles/Sec) to 2000.
6. Rewind and play the simulation to about frame 65.

   This render lets you view the general appearance of sparks, such as the amount of streaking density.

   NoteFor the purposes of this tutorial, use the Maya Software renderer with default settings. See Rendering a single frame.
7. Click the Render Current Frame icon.

   The particles appear more like sparks, but they need to be properly shaded to appear red-hot.

   

   Notice also that some sparks are colliding with the slag bin.

8. In the Outliner, select geo_bin, then select nMesh > Create Passive Collider.

   This converts the geo_slag mesh to passive collision object to ensure that these sparks collide with the bin rather than traveling through it and out of the scene.

9. Rename nRigid1 to nRigid_bin.

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