Help with "Attraction"

[mustangsRbtr]

I am working on a project where I want to have several orbiting balls bounce off each other while orbiting a central gravitational object. While I've played around with A:M for a while this is my first real project. I just haven't been able to find anything that seams to address this particular subject.

[robcat2075]

Welcome to the forum!

 

How long is the shot?

[mustangsRbtr]

Welcome to the forum!

 

How long is the shot?

 

About 2 minutes

It will be a looping background that enters and leaves the camera view. I have the flock "birds" rotating on the Y axis and they apear to orbit the central sphere but they just get farther away from the center point and never appear to collide or bounce off of each other. I have experimented with anti gravity but that just made them float or fall away.

 

Thanks for the welcome. This is my first post as well.

[robcat2075]

Do you have any image of what this might look like?

[mustangsRbtr]

Do you have any image of what this might look like?

 

Did this in Motion but it wasn't the effect I was looking for. Like the bubbles but orbiting and interaction between spheres is nonexistent. move2.mov

[johnl3d]

not sure which codec you used but the qt is blank in explorer and chrome trying to view move 2

[itsjustme]

not sure which codec you used but the qt is blank in explorer and chrome trying to view move 2

 

It will play in VLC.

 

I'm still not entirely clear about what you're after, mustangsRbtr. Would it be like asteroids orbiting a planet while bumping into each other? Or are you after bubbles? Is there a real-world example that we can use as a guide in helping?

[robcat2075]

I've never seen "HDV" codec before in Quicktime. Nothing happened when i tried to open it with VLC.

[mustangsRbtr]

This is what I've come up with so far. The flock is orbiting the center sphere. But, they appear to be stuck together not bouncing off of each other and they are not attracted to the center sphere it looks more like they are getting farther away.

 

I don't know of a real world example. The only thing that I could relate it to would be an overcrowded solar system where the planets are trying to find their orbits.

 

For some reason I am unable to upload the Animation Preview I just rendered. I will try again later.

 

In the mean time I just remembered reading something about "Springs" is there a way to attach a spring between models that would allow the main model to stay on a path while dragging the attached model and it be slung around like it had an invisible rubber band holding them together?

[robcat2075]

For some reason I am unable to upload the Animation Preview I just rendered. I will try again later.

if it's an AVI it won't upload. Convert it to a quicktime in a standard codec and that will work.

[NancyGormezano]

This is what I've come up with so far. The flock is orbiting the center sphere. But, they appear to be stuck together not bouncing off of each other and they are not attracted to the center sphere it looks more like they are getting farther away.

 

I don't know why the flock elements would be getting further and further away, but I believe "flocks" was designed specifically so that the elements would not collide. Flocks are tricky to work with in terms of controlling precise movement.

 

In the mean time I just remembered reading something about "Springs" is there a way to attach a spring between models that would allow the main model to stay on a path while dragging the attached model and it be slung around like it had an invisible rubber band holding them together?

 

Springs is also something that I believe currently isn't quite working (fully implemented or supported) in current versions of A:M. Or more precisely, I've never been successful in recent versions of A:M of getting springs to work.

 

What acts similar to "flocks" and what you are describing might be done with applying "translate to" and "orient like" constraints with lag (of 1-3 frames).

 

This animation test (done in 2009) uses constraints with lag. Not quite what you are describing, but parts of each model are constrained with lag to follow other parts of its model.

 

Or even perhaps what you need is something using a dynamic constraint?

 

Or perhaps some sort of Newton simulation?

 

Without seeing an example, it sounds like you are describing something that is done with Flash, where elements follow the cursor? or links/nodes presented graphically look like they are held together with "strings"

TheEnd3movh264.mov

Edited June 16, 2012 by NancyGormezano

[robcat2075]

I tried few basic flocking things and I find that after a few seconds they pretty much stick in one formation without much movement. I don't know if that's intended or not.

 

 

Could one use Newton to swirl some balls around inside an invisible sphere?

[mustangsRbtr]

This is what I've come up with so far. The flock is orbiting the center sphere. But, they appear to be stuck together not bouncing off of each other and they are not attracted to the center sphere it looks more like they are getting farther away.

 

I don't know why the flock elements would be getting further and further away, but I believe "flocks" was designed specifically so that the elements would not collide. Flocks are tricky to work with in terms of controlling precise movement.

 

In the mean time I just remembered reading something about "Springs" is there a way to attach a spring between models that would allow the main model to stay on a path while dragging the attached model and it be slung around like it had an invisible rubber band holding them together?

 

Springs is also something that I believe currently isn't quite working (fully implemented or supported) in current versions of A:M. Or more precisely, I've never been successful in recent versions of A:M of getting springs to work.

 

What acts similar to "flocks" and what you are describing might be done with applying "translate to" and "orient like" constraints with lag (of 1-3 frames).

 

This animation test (done in 2009) uses constraints with lag. Not quite what you are describing, but parts of each model are constrained with lag to follow other parts of its model.

 

Or even perhaps what you need is something using a dynamic constraint?

 

Or perhaps some sort of Newton simulation?

 

Without seeing an example, it sounds like you are describing something that is done with Flash, where elements follow the cursor? or links/nodes presented graphically look like they are held together with "strings"

What is a Newton Simulation?

 

On another note you got me thinking in a new direction. Would it be possible to create a model with a center main bone and lots of other spheres (20-60) with child bones that could be positioned by expressions that are related to the parent bones rate of rotations?

[NancyGormezano]

What is a Newton Simulation?

 

On another note you got me thinking in a new direction. Would it be possible to create a model with a center main bone and lots of other spheres (20-60) with child bones that could be positioned by expressions that are related to the parent bones rate of rotations?

 

Newton Dynamics - that's a whole lotta stuff - I wouldn't know where to begin with what you are describing. There's a whole sub-forum of info here. Start with looking at examples here and if you see something that sorta looks like you want - then give a holler.

 

But as for 2nd question - Give us the equation (in standard notation) that you would use to describe a sphere's x,y,z position to another sphere's rotational velocity? Depending on what you mean, I suspect that might be tricky to do in A:M as expressions does not store "previous frame data". But one might be able to do a work around of sorts. Rate of rotation to me implies "change in time"

[robcat2075]

I'll just note that the child bones will normally follow the rotation of their parent... exactly... no expressions needed. You want them to wander more? An expression could add some randomness to their motion as they follow their parent.

 

You want all of them to avoid each other? That would be tougher.

[NancyGormezano]

Here's something done without expressions and presents a couple of ideas.

 

The rates at which things revolve, and close in on each other are animated without expressions.

 

The orange ball is constrained to a crudely done spiral path that revolves around the revolving beachball. The position of the orange ball on the path is determined by the ease property of the path constraint.

 

The white larger ball is constrained to the orange ball by a "translate to" that starts out with an offset distance from the orange ball at frame 0. The offset is then animated ie, changed to =0,0,0 at the final frame, thus closing in on the orange ball over the length of the animation.

 

(I slowed down the QT movie to play at 1/2 speed, so the project will look faster. The project only has 48 frames.)

revolvh264highsloloop.mov

planets.prj

[robcat2075]

I got a look at MustangsRbtr's example movie. It looks like a particle effect, but i don't know how much that is like what you really want.

 

It's hard to imagine that going on for two minutes; that's a long time.

[johnl3d]

tried a newton idea just guessing from the request and with limited number of models

 

 

testb.mov

 

 

testb.zip

[itsjustme]

I'm still not completely clear on what is needed. Sprites in a vortex maybe?

[mustangsRbtr]

tried a newton idea just guessing from the request and with limited number of models

 

This is very close. I want to make the orbits more consistent and planetary in the way they move. So even after they bounce off of each other they still orbit around the y axis in the same direction. It may be just optical but a few times the orbit seems to revers.

[mustangsRbtr]

I got a look at MustangsRbtr's example movie. It looks like a particle effect, but i don't know how much that is like what you really want.

 

It's hard to imagine that going on for two minutes; that's a long time.

 

My original attempt was with a particle effect but I was unable to achieve the orbital interaction I want.

 

Yes 2 minutes is a long time. I don't anticipate it being more than 30 - 40 seconds with the final product. I simply replied with the current time length. in looking at my current sequence it is definatly taking way to long. I have to speed it up.

 

I don't know what I did wrong but every time I try to render a preview A:M "Halted Unexpectedly" I have been unable to get a new example to upload.

[robcat2075]

I don't know what I did wrong but every time I try to render a preview A:M "Halted Unexpectedly" I have been unable to get a new example to upload.

 

If that's v17 and you can make a sample PRJ that does that , that would make a good bug report.

[johnl3d]

attached 7 balls with dynamic constraints to central ball set at springs a few are acting up but just another attempt guessing

 

 

balldyn.mov

 

 

balldyn.zip

[mustangsRbtr]

attached 7 balls with dynamic constraints to central ball set at springs a few are acting up but just another attempt guessing

 

 

balldyn.mov

 

 

balldyn.zip

 

This looks really close.

 

Now I just have to figure out how to do it with a bunch more balls and smooth the orbits.