An easy way to add shadows to multiple actors?

ChirpinGames

Hey guys,
Just wondering if theres an easy way to add shadows to my actors.
Ive got about 10 actors per scene and it would take ages to make global variables and manually attach shadow actors to each actor. Is there an easy way to do this?
Thanks!

JCFord

Unless you wanted the shadows to move around your objects due to a light source, why not just add them to your graphics in photoshop and bring in as transparent PNG's?

ChirpinGames

Hey JCFord they cant be part of the main actor because of collision rules. Also I'd like them to be offset by about 20px so they will be a fair way away from the main actor

rlehm

Create your shadow image. For a top down shooter, just tint your plane actor black and turn down opacity.

Create 2 Game attributes. Make them Real

Call them playerX and playerY

In the actor you want to have a shadow

Constrain your players x and y to the new game attributes playerX and playerY

Then in your shadow actor, constrain his X and Y to the the first actors x and y.

Now drop the shadow actor anywhere on the screen.

Expect this to kill your performance if you do it for all your actors.

Example

Main Actor:
constrain: game.playerX to self.position.X
constrain: game.playerY to self.position.Y

Shadow Actor:
Constrain: self.Position.X to Game.playerX
Constrain: self.Position.Y to Game.playerY

Also, you can add + or - to offset the shadow so it isn't directly "under" the actor.

Example would be
game.player.X+30
game.player.Y-15

ChirpinGames

Thanks rlehm. Yep I understand all this but what im trying to do is avoid the global attributes. It would just take way to long.
Im hoping that maybe theres something where i can just spawn the shadow from the main actor and have it mimick that actor?

StuartY

Constrains are a royal pain in the ass and will hit performance

Have you considered actually embedding the shadow as translucent pixels in your actor's image, and even swapping between two sets of animations depending on whether a shadow is meant to be cast or not? This might yield better results with fewer constrains.

scitunes

one thing to consider. if you have a rectangular image (in other words NOT a perfect square) and you set the collision to circle. GS will use the center circle with a diameter equal to the shortest side of the rectangle as the collision area. So you could have a shadow that falls outside of the middle circle and it will not interfere with the collision. This trick only works with circular collision shapes though.

firemaplegames

Unfortunately there's no way to do it without killing performance.

You could unlock each of the shadow instances in the Scene and simply Constrain them to the appropriate actor.

That will eliminate the need for global attributes - however, depending how your actors move, you will still up to 3 Constrains for each shadow: x, y, and rotation.

Multiplied by ten actors, that's 30 constrains. Most of the devices would just keel over!

ChirpinGames

Cheers guys!
Thats devastating. My graphics look so much better with shadows and really give the levels depth. Without them its not going to look how I'd hoped.
Fingers crossed the GS team will come up with a way to do this that wont destroy performance.
Thanks for the advice anyways.