Sprite applications  

 sprite applications:  two locations of activation but one occurrence

This first example is by no means an effect that startles the player but it's a simple example of thinking of an effect and making it a reality. What I wanted to do was hide an atom in the wall behind a magazine stand. So what? Well, I wanted to have the magazine stand go down into the floor to reveal the hidden atom but I also wanted the effect to occur only once, from two possible locations and have the hole in the wall covered once the atom was taken. This effect might have been easier to do had the wall covering just been a door but I wanted the magazine stand to work with a sector effector, lotag, 31.
 
Here's a screen capture taken in Build to illustrate this example. The magazine stand on the left (in the floor in Build) is of the same height as the stand to the right. In the game they both appear to be magazine stands of the same proportion. You can barely see the touch plate behind the master switch sprite but that's the touch plate (and one location) that activates the effect. The player might accidentally jump up on the stand while doing battle with the aliens in this subway map and find the atom.
It is not likely that the player will jump up on the stand but if he does then the effect is activated. However, there's another location that activates it and once the player grabs the atom and walks over the top of the stand (now in the floor) the stand will be activated to cover the hidden area. I suppose I was thinking more of aesthetics than a cool effect but that's what I wanted. The biggest problem was using two uniquely tagged touch plate sprites and two master switch sprites for one effect. I wanted two locations of activation but only one occurrence.
 
Big deal?  Well, I bet you've already thought of two or three really  cool ideas where you could make use of this particular sprite trick and that's what I'm trying to do here: give you ideas.

The white arrow is indicating the magazine stand across the subway platform, the red arrow points to the alternative touch plate sprite which also activates the effect. If the player doesn't activate the effect by jumping up on the stand, then he will activate it as he leaves the subway. So, how does he find the hidden atom? Given the map's design, the player has got to come through this area again and after a big battle...he'll be glad to find the atom, then. So, either way, the stand goes down into the floor once revealing the hidden atom and returns to its original position once the atom has been retrieved.



Here is the 2D schematic for the set up of this effect:




Notice the orientation of the sprite's tails. They had to be facing the direction that they are for this effect to work with the two master switch sprites and two different touch plates. (Second touch plate not shown with hitag, 1 and lotag, 8055). The effect also wouldn't work unless the master switch sprites were given a hitag. When you try to create your own effects, experiment with the orientation of the sprites and even which ones you place, first. Try to get the effect to work under normal conditions before doing the rest. For example, I first got the effect to work with one activating touch plate, one master switch, and a sector effector (normal). Then I tried different things to get the over all effect to work the way I wanted it by experimenting.