Making of Muridae Massacre: Managing Advanced Effects

Practically every game today makes use of particle effects. From the flash of a disappearing block in a puzzle game to the spectacular explosion in an action game, effects add to a game’s excitement and realism. Virtools Dev presents a wide variety of options with which to create effects: particle systems, custom building blocks, and animation playback. Advanced particle effects may involve several of these options simultaneously, typically including several particle systems. The following are some tips and notes taken from the MM team’s experience in making complex effects more manageable in a production setting.

During early experimentation, it became clear that the team’s artists would be able to utilize Dev’s particle systems and tools to create suitable visual effects. However, the greater concern became how to manage the use of complex effects from a production and programming standpoint. The production goal for the MM effect scripts was to set up the system to be as modular as possible. Effects should be easily, so that adding or modifying an explosion’s visual component would be straightforward. The artistic goal was to seamlessly mix multiple particle systems with animated objects, and to enable easy editing of a single component—such as the smoke in an explosion—without having to redo the entire effect.

The approach used in MM was to parent all components of a single effect to one 3D frame. The components of a landmine explosion—fire, smoke, shrapnel, and shockwave—were linked to one 3d frame, for example. This provides the convenience of a single object—the root 3d frame—that must be copied and placed in the world to create an effect. If the artist decides to replace the flame particle system in a weapon explosion, editing is straightforward. He doesn’t need to worry about altering any schematic other than the particle system he wants to tweak, so long as the new flame effect is a child of the 3D frame used as the root of the entire effect.

For example, the stunmine explosion effect in MM is organized as follows:

The FX – Stunmine Waves 3D frame manages animated objects that scale outwards to produce a shockwave effect. The other frames manage particle systems for the sparks and shrapnel. A script on the root of the effect deletes the entire hierarchy when the effect is completed. This simplifies things, since the code that creates the effect doesn’t need to worry about removing it; it’s a simple matter of copying the root object and setting its position where desire.

This setup is a little more difficult to debug because the effect hierarchy is self-deleting. The original copies of the effect’s scripts should be disabled at the start of the composition. Creation and debugging of effects should first be done in a separate file with a placement system similar to the included example. Once the effects are finalized, they can easily be imported a project’s environment.

The included composition "effects example.cmo" has a few effects from the MM project. For more information on the technical setup of this technique, browse around the included example.