Creating and Rendering Sparks

This session demonstrates sparks from a collision, as well as from a pulsing (expression driven) emitter. Starting from scratch we generate the required elements to produce the effect: volume emitter, particles, fields, animation, expressions, Collision Events, particle shader and utility nodes. Sparks are a fairly common, yet simple, effect that can be effectively created using Maya dynamics.  For rendering we utilize the Tube software render type as the final output, yet we also discuss how sparks can be rendered using the MultiStreak hardware render type.

                                   

The following example uses hardware particles to create spark from a circular cutting saw and examines how they can be integrated with a scene.

Create a ground plane and an emitter.  Sparks will generally streak as they move through Space and will exhibit several other properties in terms of lifespan and colour. Set the emitter to be directional, so that sparks can fly off in the direction of the cutting saw’s rotation and Set the direction to be  1.0 in Y. It will be far easier and more intuitive to have the emission occur in a single direction and just rotate the emitter than to control the sparks’ direction Through the direction attribute.  Set the rate to 300, speed to 15.0 and change the particle type To streak, clicking the Current Render Type button so that you can start changing the look of The sparks.  Several particle attributes will need to be changed in order for the sparks to look like the real thing:

Spark shape Lifespan Colour

Spark shape will be combination of the render attributes scaled by the speed of the particles, so it is important to get the movement right first. Rotate the emitter so that the particles are being emitted at a 45 degree slant to the ground plane and add a gravity field a low magnitude but no attenuation so that the particle want to return to the ground. Once the speed is correct, set the TALE SIZE and LINE WIDTH attributes so that the sparks being to take shape. Because the tails extends backward from the spark position, you will need to change the min/max distance for the emitter so that the spark tails appear from the emitter and not before it.