Unity: Creating Inventory Systems - Creating Games with Unity and Maya - page 461

Tutorial 16.2: Keys
Hopefully, this will be a fun tutorial. In the process of this tutorial, we'll make
use of the techniques we've covered in the past tutorials. By assembling these
skills in a new way, we'll have a new mechanism in the game.
The process will go like this. First we'll need to create a trigger that checks
to see if the player has the key when the player enters it. If the player does
indeed have the key, the door will open; if the player does not, a text prompt
will pop up to alert the player that he needs the key. We'll create a PickUpKey
function that fires when the player's ray is cast upon the key and the player
clicks it. When the player clicks the key, we'll make the key disappear from
the scene, but create a GUI element to indicate that the key is on the player's
person. It's going to be fun!
Step 1: Create a new GUITexture to show the key. Create a new GUITexture
(GameObject>Create Other>GUITexture) and name it KeyIcon . Use the
texture Icon-Key from the 2D Assets folder to define its texture.
Step 2: Place the key in the top-right corner of the screen. Select KeyIcon
in the Hierarchy and in the Inspector change the Transform X and Y values
to 1. Change the Pixel Inset values to X = -70 , Y = -70 , Width = 64 ,
Height = 64 ( Figure 16.6 ).
Figure 16.6 Placed key icon.
Why?
The image is 64×64. With the GUITexture at 1,1,0, the bottom-left corner
of the image is at the top-left corner of the screen, meaning that the
image is off the screen. By offsetting the pixels by -70 in both X and Y, we
slide the image back onto the screen with a 6-pixel buffer above and to
the right.
Step 3: Now that you can see what it will look like when visible, move it off
the screen. Select KeyIcon in the Hierarchy and in the Inspector, change
the Transform X = 1.1 .