[behavior] rex_light

Johncw87 's trace (raycast) plugin is better then this behavior. So I will recommend user try that plugin first.

Here is the demo of reflecting using trace (raycast) plugin. (source capx)

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rex_light : adjust width until hit obstacle (not a real lighting system)

Demo1: lights and reflection ( laser)

Demo2 : project shadow ( left/right/up arrowkey to move the character)

Thank you so much, this is gonna be useful when making lasers for a game :D

Another thank you for sharing this & all your other c2 addons.

I just wanted to confirm something about this behavior- does ReflectionAngle only work for the sides of a sprite that are parallel to the sprite's angle?

mattb

The parameter of expression:ReflectionAngle is the normal vector. I only use the angle of the wall to be this input, so that it might be strange at the edge of wall, like your image 2 shown.

After spending about 2 days figuring out how to make lasers and bullet-tracers, I find this excellent plugin that does it better (significantly faster according to the debug mode) and far simpler.

However, I wonder if I might request a feature. Is it possible to exclude certain instances from the collision triggers? The player unit and his allies as well as enemies all have Shields. I was hoping the light behavior could ignore collision with all instances of the Shield object belonging to the attacker and his allies.

The way I did it before was to save the attacker's UID and faction name in the laser/tracer's instance variables then make the laser/tracer ignore shields and allies of the same uid/faction. Basically, the laser/tracer would ignore collisions with objects from the same source.

Norbingel

Set the collision of ignored objects to "Disable", so that they will not be tested.

Kyatric

Please help me move this thread to "Completed Addons" section.

Moved.

Kyatric

Thanks!

rexrainbow

I don't think it'll work. I need the unit's shields to allow it's own laser through, but block enemy lasers so I can't disable collision. If it could ignore checks for certain instances only, instead of all objects of the same type, that would do it, I think. It's what my laser is doing now but testing shows your plugin is significantly faster (not to mention a whole lot easier to do).

Norbingel

Since the checking is not automatically, you could disable the collision of target instance only, then run action, finally reset collision to enable.

Edit: to mark the ignored instances, you might use my rex_ginstgroup plugin.

I will test later when I can but when I enable collision again, wouldn't it detect the collision again and set the laser length accordingly? What happens when the enemy laser is hitting the shield at the moment I disable collision? Then the laser would get through when it shouldn't.

That looks like another handy plugin, thanks!

mattb

The parameter of expression:ReflectionAngle is the normal vector. I only use the angle of the wall to be this input, so that it might be strange at the edge of wall, like your image 2 shown.

So if I wanted to get correct reflections on all sides of a rectangular sprite, the way to do this would be:

1. determine which side of the sprite is hit (by comparing the angle between sprite & hit point)

2. for the 2 sides of the sprite with incorrect reflection, set the reflected angle of a Laser sprite to 'Laser.Light.ReflectionAngle(Sprite.Angle+90)'

Is this right?

(I've tried to set this up & I think my code for step 1 is faulty, but just wanted to confirm that I'm on the right track)

mattb

I guess... you might use 4 edges (sprite) to compose a full wall. Each edge maintains a face of reflection.

Got the events working at last. Capx is attached below...