The Magic Rock

The magic rock is a special weapon, which, when held in the player's inventory, causes any AI with whom the player comes into contact to die. This is an effect achieved with the use of Sources and Receptrons (known as S&R's). A simple analogy would be to think of the source as a river and the receptron as a waterwheel. The river's power causes the waterwheel to spin, in much the same way as a source causes a receptron to work. The varying stimuli available can be considered separate rivers which control individual wheels. For example, the wheel in stream A cannot be turned by stream B, and stimulus type A cannot cause receptron type B to react. For a more in-depth look at how S&Rs work it is recommended that you read Totality's Sources and Receptrons, for teleporting and timing guide.

Information in pink provided by dOom.

Setting up the rock

Step A - Adding The Source.

The rock is the item that will cause the action - in this case, the death of an AI - to occur, and therefore it is logical to make it the source in this example. After creating the rock you need to go to:

properties->add->act/react->sources

This brings up the following box:

Now select the "Add" button. It brings up a menu that lets you set a source on the object. The rock is set up as follows:

  • Object: This is the object you wish to be the source. Place the number of the rock here.
  • Stimulus: This is the types of stimuli you wish the source to emit. In my case I chose ToxicStim. Alternatively you could make your own stimuli, as described in the aforementioned Sources and Receptrons, for teleporting and timing guide.
  • Propagator: Sets up how you want the stimulus to be emitted.
  • Radius: tells DromEd that you wish the source to be emitted into a set radius whilst in the player's posession.
  • Intensity: This is the strength of the emission. As I used ToxicStim the intensity must remain at 0 or it will cause Garrett to be injured when the rock is in his possession.

    Next we must set up the appropriate shape data by selecting "Edit Shape":

  • Radius: This is the distance, in feet, at which the source will be emitted from the object. It is worth playing with this distance to achieve your desired affect.
  • Flags: Checking the "Line of Sight (Radius)" flag means the rock will only affect receptrons directly in front of Garrett.
  • Dispersion: This determines how the source flows from the object. It can be set to:
      None - everything in the radius is hit for the specified intensity
      Linear - intensity diminishes with distance linearly. So if you are 2 feet away you get 1/2 the intensity you do at 1 foot.
      Inverse Quadratic - the same as linear but proportional to 1/D^2 rather than 1/D, so at 2 feet it is 1/4 the intensity at 1 foot.

    When you have these settings as you wish, choose ok. Finally the Life Cycle needs setting via the "Edit Life Cycle" button.

  • Flags: The "No Max Firings" flag is used to prevent the rock from "dying". If this is not checked only a set number of emissions will be made before the source ceases to work.
  • Period: This is the length of time, in milliseconds, between source emissions. In the case of the rock, it is set up to emit the stimulus once every half-second.
  • Max Firings: If you wished the source's life to be limited, here is where you would set the number of times it would fire before death (death being a cessation of function).
  • Intensity Slope: Intensity slope is added to the intensity with every firing, so if it is 1, then at each firing the intensity increases by 1.

    Set up as shown above, the magic rock is now an active weapon, although at this stage it has nothing to kill.

    Step B - Placing the rock in the player's inventory.

    By default, the rock is set as a junk item and does not stay in the player's inventory. To change this, the following properties must be altered:

    In properties->add->Inventory->Type

    Select "Item" from the drop-down menu.

    This causes the rock to be placed into the player's inventory when picked up.

    We also need to inform DromEd what type of item the rock is. This is done by setting the "Combine Type" in the Engine Features Menu.

    This should be something unique to the object in question. In this case "Magic Rock"

    Finally we must give the rock a name that will be displayed in the inventory. Select
    properties->add->Inventory->Object Name

    There are two sections to the name. Name_MRock can be used to set up an inventory name via a string file. However by adding the name you want displayed in brackets "Magic Rock" this can be avoided.

    Step C - Making the rock look the part

    So now we have a functioning weapon that can be carried around in the player's inventory, but it looks both cumbersome and dull. Time to spice things up a little.

    The first thing that needs fixing is the size. Rocks are big and unwieldy. A weapon should be more manageable. Two things need altering: the graphical size and the physical size. The graphical size is set using the dimension settings in the bottom left of Dromed.

    The physical size is altered via
    properties->add->physics->model->dimensions

    The rock is a sphere, so only the radius needs to be altered. This should be set to half the height of the graphical size of your rock.

    The rock is now a reasonable size, but there is still no visible indication that it is magical. I added two features to make it stand out from the crowd.

    A glow was added using
    properties->add->renderer->Extra Light

    This can be set to a value of -1-1. Pick a setting which you find appropriate.

    Finally I opted to add a particle effect to the rock. Particle effects are found in the object hierarchy under SFX. Rather than mess around with attempting to destroy the particle when the rock was picked up, I opted to link them together via a particle attachment:

    In the "from" field you should place the number of the particle you have chosen. In the "to" field put the number of your rock. DO NOT place them the other way around or you will end up destroying both the particle and the rock. You also need to set up the position of the join. Select the link number and press the "data" button. In the box that opens, set the joint to "object" and leave the other fields alone.

    Having done this I discovered that, in Thief 1, this has the bonus effect of placing the chosen particle around the player when s/he has the rock in his/her possession.

    Setting up the AI

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