# Space Game Parts falling off

This topic is 1747 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

Hi I am making a Space game and i want the enemys to throw off their parts when they have lost a lots of life, but the single parts also should be animated. So how can I make sth like that? Sry for my English I am from Austria ;)

##### Share on other sites

I assume the video is not from your game?

You could make your ships have multiple hitboxes, and when one has lost all its health it triggers the event that makes the ship lose the part the hitbox was hitboxing (?) for. Then the easiest way would probably be to make the ship consist out of multiple animated sprites (just make a class, like ShipPart or something like that) that you can easily make fall off. Or you could have multiple ship sprites for different damage conditions, and then when the wing falls off just create a new game object where the wing was.

I probably explained that quite badly, but I was a bit confused by the question. If you could elaborate a bit, that would be great :)

##### Share on other sites

Thanks a lot Dobbydoo ;)

The video isnt from me but i like the way the parts fall off there

My question was how to make an enemy consist of more than one animation parts so your answers helped a lot ;)

But how would you place the different animating parts together so that the proportions are correct? Just put the center of the animations all on one point on the screen?

And so that every ShipPart holds a texture for its wings for example and when the parts are destroyed I just create a new Object with that texture and rotate it like in the video?

##### Share on other sites

But how would you place the different animating parts together so that the proportions are correct?

Each ship part would have a transform that specifies its offset from the ship's local origin. With a suitable vector/matrix math library, it should be relatively easy to overlay the additional parts onto the base enemy structure - which itself might just be a part, just with a transform that does nothing!

And so that every ShipPart holds a texture for its wings for example and when the parts are destroyed I just create a new Object with that texture and rotate it like in the video?

Precisely, that is one way to do it.

##### Share on other sites

But how would you place the different animating parts together so that the proportions are correct?

Each ship part would have a transform that specifies its offset from the ship's local origin. With a suitable vector/matrix math library, it should be relatively easy to overlay the additional parts onto the base enemy structure - which itself might just be a part, just with a transform that does nothing!

Just to expand upon this answer, if rotations are not needed, you could just specify the center of your ship as an origin point, and then draw the parts of the ship at an offset from the origin.

For example: If you have your origin at your ships center, then you could draw a part of the ship at origin - part.offset. This way the parts will always be drawn at the offset specified for any given part.

And so that every ShipPart holds a texture for its wings for example and when the parts are destroyed I just create a new Object with that texture and rotate it like in the video?

The other way you could this is to create the Objects with the ship, by for example including them in a list in your ship class,  and then just update the positions of the Objects with the origin and offsets. The advantage of this would be that you could have each part behave differently and animate while still being attached to the ship, so just having more customization really. I think the method you described would be faster, but I don't imagine either method will make much of a difference performance wise unless you're thinking of having thousands of ships on-screen.

Edited by Dobbydoo

##### Share on other sites

Guys thanks a lot ;)

I am on the way on implementing it like you said and your answers were golden ;)

##### Share on other sites

Here's a little function I use quite a lot for getting the offset position of a sprite around a rotated object. It's particularly useful for ships made out of multiple parts that have varying positions.

Point GetRotationOffset(Point p1, float rotation)
{
Point newPos = p1;
newPos.x = (p1.x * cos(rotation * radian)) - (p1.y * sin(rotation * radian));
newPos.y = (p1.x * sin(rotation * radian)) + (p1.y * cos(rotation * radian));
return newPos;
}


For stability you don't want to use this to set your part's position every update. Leave it at it's default value and only use this during the draw step or in situations where you need the offset position (like getting the barrel position for a turret). Also make sure you add the returned value to your base object's position.

Edited by Lemunde

• ### What is your GameDev Story?

In 2019 we are celebrating 20 years of GameDev.net! Share your GameDev Story with us.

• 17
• 14
• 10
• 9
• 11
• ### Forum Statistics

• Total Topics
634097
• Total Posts
3015505
×