This is the User Guide for a holo-emitter system that works in the virtual world Second Life (and it should also work in OpenSimulator). The system is a set of scripts written in Linden Scripting Language (LSL). Those scripts are open source (GPL2) so you can change them to suit your needs. You can get them from a variety of places:
In Star Trek, there's something called a holodeck, which is a room where you can simulate just about anything, from a beach resort to a spaceship. You just tell the computer what you want and it appears. The things that appear are holograms and they are generated by so-called holo-emitters.
I made something similar for the virtual world Second Life (and it should also work in OpenSimulator). You click the holo-emitter, it gives you a menu of scenes, you pick a scene and it appears. Simple.
I made it so that the scene can be spread out over an entire sim. That way, you could easily change the sim (e.g. from a city to a meadow) to suit your mood. You could also use the holo-emitter system to move scenes from one part of a sim to another part, because the objects in a scene move relative to the holo-emitter. You'd just pack up the scene at its original location, move the holo-emitter, and rez the scene again at the new location.
I hope this guide is enough to get you started. I assume a certain amount of familiarity with things like inventory, permissions, and building.
There are four scripts that work together to make the holo-emitter system work. They are named:
Object Script A
Object Script B
and there may be a version number (like “v1.0”) tacked onto each name. Please make sure you have all four scripts or the system won't work.
The holo-emitter (an object) contains a set of scene-containers (also objects). Each scene-container contains a set of objects (the objects that make up a scene). To use my holo-emitter system, your scene must be made up of objects that you can modify and copy. To repeat: you must be able to modify and copy every object in your scenes. (You don't need to be able to sell/transfer though, unless you want to give or sell the loaded holo-emitter to someone else in the future.)
When you click the holo-emitter, it looks at its contents (scene-containers) and uses that to give you a menu of scenes bases on the names of those scene-containers. When you select a particular scene, the holo-emitter rezzes that scene-container. The scene-container then rezzes all objects in its contents and then vanishes. The contents fly to their proper position then stop. Voila!
Now let's go through the steps to pack a scene into a scene-container object and then put the scene-container object into a holo-emitter object.
That's all. Next time you click the holo-emitter object, it will automatically detect the new scene-container object and add it to the menu of scenes.
One user reported that she could use the system to rez scenes, and so could others, but as soon as she logged out, others couldn't rez scenes anymore. It would just fail silently. The emitter was on a parcel deeded to a group (i.e. group-owned land). We found that the problem got solved by 1) deeding the holo-emitter object to the landowning group and 2) checking the box in “Top Menu – World – About Land – Options” to allow group members to “Create Objects”.
Scenes can have any number of objects. Of course, the more objects there are in a scene, the longer it will take for it to rez. (Note: there is a built-in, hardwired delay between the rezzing of each object in a scene.) A holo-emitter can also hold any number of scene-container objects, but only the first eleven will show up in the blue pop-up dialog box when you click the holo-emitter (and the twelfth button will always say 'Clear'). Feel free to change the holo-emitter script so that more scenes could be chosen (e.g. maybe change it to have a hierarchical menu or use chat commands instead).
If you move the holo-emitter so that an object in a scene at the new location would have its center under the ground, then that object will not go to their correct position (relative to the holo-emitter) – the object's center will go to a point on the ground near the correct position instead. This happens because an object can't move itself so that its center is below ground level.
If you move the holo-emitter so that an object in a scene at the new location would have its center outside the current sim, then the object will try to move itself there, but it will probably fail and end up in your “Lost And Found” folder (in your inventory).
If you have two or more holo-emitters in the same sim, then there will be crosstalk and it won't be pretty! That doesn't mean it's impossible. To have two or more holo-emitters in the same sim, you just need to edit the “Global constants” section at the start of each script (for those that have one). Change the channel numbers and make sure they are consistent (e.g. HE_channel must have the same value in all scripts). A copy of the Global constants section of the “Holo-Emitter Script” is shown below:
// Global constants // These should be changed if there are any other holo-emitters // in the sim, both here and in all other scripts integer delete_channel = -3423489; integer menu_channel = -1847395; integer HE_channel = -9385735;
If you don't want an object in a scene to vanish when you select “Clear” or when a new scene is chosen, then remove Object Script B from the object's inventory. Object Script B is pretty simple: it just listens for a special command (on the delete_channel) to tell it to delete the object in which it is contained.
This user guide is copyright © 2012 Troy McConaghy. It is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License. (The scripts and software code for the holo-emitter system are under a separate license. See the code itself for more information.)