Emitters are one of the newer SketchyPhysics tools. Accessed through the UI of an object or group, emitters allow you to propel copies of the object along its Z axis. Unfortunately, emitted objects will lose all settings such as: state (static, ignore, etc.) and joints that it is connected to. This means you cannot emit a whole car unless it has no joints in it. However if it is emitting a group and an object within the group is set to 'ignore' that object will still be ignored. This small feature is often used in guns as making the gun powerful enough to do any damage usually causes the simulation to glitch and fire through things. By grouping the "ammo" (emitter) with another object many times larger and making that object ignored and hidden it will retain those properties. The round will be heavier and require less power and still do huge amounts of damage without going through everything. With the exception of grouped objects as shown previously hidden objects will no longer be hidden when firing.
- Strength: The force the object that it is fired at. Setting this to 0 causes copies to appear on the same spot as the emitter and float out of each other as if 2 boxes had been placed in the same spot before the simulation started.
- Rate: This is the amount of frames between each copy being emitted. Set to 100 and there will be a copy every 100 frames. Setting this to 0 will turn the emitter off
- Lifetime: This is how many frames the copy will last. Set to 100 and the copies will last 100 frames each. Setting this to 0 and the object will last until the end of simulation. Unlike the other sections, this can only take a concrete value and not a script.
The emitter can be controlled although it is limited. Formulas can be entered in strength and rate but not lifetime. As far as the author of this article knows, the emitter only supports the values of on, (1) and off, (0). Any value over 0 will turn the emitter on. A value below 0 such as -1 will cause the emitter to fire the opposite direction. This means your emitters are limited in control.
Adding settings to emitted objectsEdit
There is a way, although experimental and involving advanced scripting, that can add properties to emitted objects. This involves adding a script into the onTick field of the emitter that 'hacks' into SketchyPhysics and can then add properties to the emitted objects. However, it has only been tested with the onTick field, and does not support emitted objects having a lifetime. Here is one example and another one.