Okay, checked out the example (and I've been reading the wikis.)

This is closer to katamari goodness, however the ball has now become a nightmare to control and sometimes has a habit of just shooting off into the distance at top speed.

Also, the grouping thing will also be a problem.

I think I can think of a way to solve a few things.

Referencing the original katamari video I posted, the ball seems to move as an invisible circle like you mentioned, not literally moving using every object as an actual attatchment. See how lots of the objects on the ball lay behind the floor background? So it seems that your first example would work better.

Perhaps there is a way to simply "paste" on anything you pick up to the ball, and have an invisible ball that follows your visible ball. This invisible ball, if say, is 5cm, picking up a 2cm object, no matter its shape, will become 7cm, but the original ball does not grow. So you have a "pickup area" ball and the physical ball that the player sees. I think this would also take care of your grouping problem, as no object would have to stick to itself - everything is sticking to the ball, creating the illusion that the things that stick to the ball are sticking to the other things on the ball, but really they're just sticking to the ball. And you wouldn't have to deal with a lumpy, erratic moving ball (which would be cool because it's like that in katamari, but not so cool in this version because construct's physics aren't entirely stable.)

Perhaps if there was some way to make the inivisible ball stretchy, or liquidy, odd objects would cause a satisfying limp for the ball - but this is probably more effort than it's worth

So theoretically, nothing has to have physics except the ball. Everything else can be moving on its own path or whatever. Watching the 2d katamari video, I don't think anything but the katamari has physics (although I may be wrong, I wasn't looking out for it when I watched it.)

Does that make any sense?

Okay, got the family thing down. Although will this method work?

Say the katamari is 5 cm. you pick up a 2cm object and now your katamari is 7cm.

Will construct still think the katamari is 5cm, because the katamari and the object are only hinged together, but not considered the same object? In MMF2, I'd fix this with flags.

Also, what do you mean double hinging? I know how to hinge, but the object doesn't roll with the katamari once hinged, it just makes it drag awkwardly.

Right now, it's like this:

<img src="http://img244.imageshack.us/img244/1362/code.png">

All I changed was the grouping thing, no hinging or anything fancy. It only picks up things at least half as small as it is, which is good. But it's still far from what we're trying to achieve - the ball needs to roll on what it's picked up, not just pasting images of what it's picked up to the outside of the ball.

I'd suggest the second one, although you might need to do what they did in katamari, and have smaller versions of each sprite that you load up as it gets bigger to save vram, also maybe something using canvas to paste all your sprites to everytime you get a major zoom , so you're not keeping track of the rotations of hundreds of objects

imagine that you made the exact same red circle, without physics

and you made a pink circle with physics the exact same size, but set to invisible

every frame you told the red circle to set it's location and angle to the invisible pink circle

so far it behaves the same, but when you pick things up, you figure out a math formula that will change the shape of the invisible pink circle so that it circles the redball and the junk, and you'd have to find other formulas and expressions to position the ball on this new pink one, but the idea would be something like this:

Yeah, I was thinking the same also with the smaller versions of sprites. If this is anything like what I want it to be like, there's going to be hundreds of objects and I'm not sure if people's computers could handle it. But I am very new to construct and I have no idea how to use canvas to "take a screen shot" of the katamari when it goes through the zoom process so that we're not rolling the actual ball anymore.

I'm very new to Construct but I'm well-versed in MMF2 and I've been using it for years. I very recently switched to construct because it seemed much more powerful.

The pink ball is a great idea, but I'm not well versed enough in Construct to even start thinking about how to code something like that... I'm sure someone could do it though. I need a team of people for this game, I'm thinking.

Hmmm this might be doable with straght physics objects... using two hinges per object instead of one would effectively "weld" it to the new object... in theory.

I might have a tinker later with some ideas and see if I can figure something out. I love the Katamari games (no pun intended), so it would be fitting to have a Katamari clone made with Construct.

~Sol

That was my initial thought, although I couldn't find a way to get the objects stuck to the katmari stick to each other. See, an object that is stuck to the katamari needs to pick up other objects that it touches. But the objects can't stick unless one of them is stuck to the katamari, otherwise you'd have objects stuck together everywhere. So we need something like this...

If the katamari touches an object...

If object is smaller than katamari...

Stick the object to katamari

Turn on variable "stuck" to object

If variable "stuck" is on...

On collision with new object...

If new object is smaller than katamari...

Stick new object to object

Turn on variable "stuck" to new object

I'm actually working on a lot of art and sound for this game and it's going to have an interesting paper cutout style, or perhaps a retro one. But if anyone is interested in joining the team with me and helping with coding, I'd love it.

Another important feature is that every object is assigned a size, and that the katamari automatically picks up anything smaller than it. This way you don't have events for EVERY OBJECT that the katamari picks up. Something like this.

(Object is 5cm, size is a variable. Katamari is 55 cm.)

If Katamari size is > than object size, pick up object.

On collision with object smaller than katamari...

Stick object to katamari

Add object size variable to katamari size variable.

So the katamari should now be 60cm.

However there is a problem with this too (other than the fact that I don't know how to code it.) The katamari needs to only pick up objects that are at least 40% or maybe 50% smaller than it. You don't want a 200cm katamari picking up a 199cm object.

wow, that was super helpful, thanks tons!!

okay, a couple things. the example looks pretty good. do you suggest the actual ball should grow as more and more stuff is picked up, or just that the stuff is getting more and more?

you lost me on the invisible stuff but it all sounds very good on paper.... also, how will i be able to have the camera zoom out as the ball gets bigger? would there be an easier way to "simulate" this effect? and how will the ball know to only pick up objects that are bigger than it?

I'm working on a 2D Katamari Damacy game that mimics this:

I'm using Construct, but I have hardly used it before and I need bigtime help.

Basically, I need to create an engine that allows you to have a physics ball that can jump, roll, pickup objects smaller than it, and stick those objects to it (they need to rotate with the ball)

But I really have no idea where to start. Could anyone help me with this? Seriously, I'm lost.

So can anyone help?

I understand this shouldn't be TOO difficult in construct. But I'd like the camera to zoom out as the ball gets bigger...