Position constraint helper to object that already path constrainted to spline

[IOSIFSTALIN2015]

1. I have first object (helper-1) that path constrainted to spline-1
2. i have another object (camera) that path constrainted to another spline

what i want - i need to create helper-2 that would control position first object (helper-1) while it
will be following along its own path (spline-1) … then i will constraint this helper-2 to camera and do some animation when at some part of spline-1 my helper-1 moving by its own creative way and then smoothly follow camera.

question - how it possible to constrain 1 object (helper-1) to path(spline-1) and at the same time to helper(helper-2) ?

[leeminardi · Accepted solution]

I've read your question several times and am still not clear of what you want to achieve.   Your question "... how it possible to constrain 1 object (helper-1) to path(spline-1) and at the same time to helper(helper-2)" could be addressed by assigning multiple Paths to an object and changing the weight factors at different frames or perhaps through the use of a link controller but I would need a better understanding of your goal.

Could you restate your question in terms of a sample scenario?  For example,

frames 1 - 50 dummy1 follows path1 and free camera follows path 2

frames 50 - 100 camera follows ...

[IOSIFSTALIN2015]

Its very easy. 

Ok...you have rail - path 

you have wheel on that rail 

 wheel constraint to rail ....easy 

i want that wheel moving on this rail not only driving by path or by animatiom keys ...no - i need to control 

this wheels moving on path BY HELPER-2

[leeminardi]

What aspect of helper 2 do you want to control the % Along Path parameter of the path constraint of helper 1?  For example, you could make the x coordinate of helper 2 define the %-along path parameter via a Wire Parameter or use an expression controller if a more complex association. 

[IOSIFSTALIN2015]

i want to control position of Helper-1 on path BY HELPER-2. Thats all that i need. 

And whats the problem. If i constraint Helper-1 to path (with path constraint) its ok...bit at the same time

i cant constraint Helper-1 to Helper-2, if i doing his Helper-1 detaching from path. 

How it possible to control moving Helper-1 on path by Helper-2 ?

[leeminardi]

When you assigned a path constraint to helper-1 you've established that its position will use a % Along Path parameter to control its position.  By default the parameter is 0% at the start of the animation and 100% at the end.  You can of course change the timing and % values by editing the keyframes.  If you want  to control these % values via another helper (helper-2) then you need to establish a relationship between helper-2 and the % along value of helper-1. 

You could, for example, set the %-allong value of helper-1 to be a function of the path-along function of helper-2. 

You need to define how you want to relate the position of helper-2 to helper-1.

In the following example the position of dummy1 (top) is a function of the location of the camera (bottom). If the camera is less than 50% along its path the dummy is 2 times further along its path.  When the dummy is 50% along its path the dummy starts to move from the end backwards.

[IOSIFSTALIN2015]

Thanks. When i told about camera it was a little bit over-information, lets keep it simple. Please show what i must do to achive this result:  In viewport i manually moving helper-2 and it moves helper-1 along path

[leeminardi]

YOu haven't stated how you want to relate the position of helper-2 to the position of helper-1 along the  path.

In the following example I have used an expression controller to control the position of helper-1 along the path as a function of the position of helper-2.  If helper-2 is less than 300 from the sphere's center then helper-1 is at the start of the path.  If helpr-2 is more than 600 from the sphere then helper-1 is at the end of the path. If helper-2 is more than 300 but less than 600 from the sphere then helper-1 is proportionally along the path (e.g., if it is 450 from the sphere it will be 50% along the path). 

HOW DO YOU WANT TO RELATE THE %-Along Path OF HELPER-1 TO THE POSITION OF HELPER-2?

[IOSIFSTALIN2015]

linear direct relate - helper-2 moves = helper-1 moves at the same time and speed (but on path) 

yep...i just want to drag-move helper-2 in horisontal direction by hand for animation(and at the same time it will be constraint too - to camera) and this helpers-2 movement will move helper-1 along path, thats final system exacly what i want. Very simple. 

1) camera to path - easy 

2) helper-1 to path - easy

3) helper-2 to camera - easy

4) helper-2 controls helper-1 on spline - how?) 

[leeminardi]

I think what you are asking for is that you want to:

1. freely move helper-2 in the + or -  x direction (i.e., horizontally) 

2. this causes the  movement of helper-1 along its path 

and

3. the camera along its path

In addition you want the speed of helper-2 and helper-1 to be the same. 

It's not clear what you want to achieve by linking helper-2 to the camera  (select and link).If helper-2 is the child of camera then you can move it without affecting the camera.

If you use a wire parameter for all three objects (no object linking) you can tie the movement of all three together such that you can select and move any one object and the other two will move along their path.

In the following I have created a horizontal path for helper-2 and wire them to each other.

[IOSIFSTALIN2015]

Thanx i will try it tomorrow and answer then. The reason why i am attaching helper-2 to camera (camera constraint to the path) is creative freedom without a lot of calculation (i am new in controllers but i want achive result asap) in much more comlex scenario. My helper-1 that path constrainted too will be "control helper" for craft director dummy that will control mars rover that will travel along surface. 

in this way i think its very simple chain and i will get very usefull system 

1) camera moving along path (one click) - helper-2 moving-driving by camera(one click to do) AND AT THE SAME TIME freely by hands (for extra keys at some point of travel far to camera and in some point close(manual keys by my hands) and some part of travel straight to point of camera view (because it - helper-2 constraint to camera that what we did) 

2) helper-1 moving along path(one click) - craft director dummy(child of helper-1) - one click to do

3) helper-2 controling movement of helper-1 by camera(because it constrainted) and by hand-keys 

That will give us very smooth cinematic effect just by automatic (by camera, all starts in it) and manual(extra keys) method. As a result in one part of video rover will smothly "entering" view and then following straight to camera and a lot of things. I will show you it. 

Thats why it very important to make helper-2 control helper-1 how it will be travel on path-constraint!

[leeminardi]

If helper-2 is going to control the movement of helper-1 then it must do it by adjusting the %-along-path parameter of helper-1.  If you want to temporarily disassociate helper-1 from its path you can do it via a link controller (not to be confused with a link constraint). 

[IOSIFSTALIN2015]

I did, but it work not i need. 

camera - on path - ok

helper-1 - on path - ok

helper-2 - on path - ok

camera parent to 1 - 1 parent to 2 - ok 

camera moves on path - 1 and 2 move on their own paths - ok

BUT....at the same time i CANT move helper-1 on path by hand...its completly lock to camera and thats not what i need. I need all the same = camera move and helper-1 move(by camera) and helper-2 move (by helper-1) but in this chain i need to move helper-1 by hands-keys while its moving by camera on path

[IOSIFSTALIN2015]

I did fake hand made video for simulate what i need as result https://www.youtube.com/watch?v=TXXB27a9jGU&feature=youtu.be

1) camera on path - ok 

2) helper-1 on path - ok 

3) helper-2 - its no need path at all - just link for helper-1

what we see - camera moves on path or by hands  and helper-1 moves on path too driving by camera - ok...

but at the same time it can be animate by hand-keys and then (when keys end) come back to straight folowing camera....that the goal 

[leeminardi]

Is the result that you have a satisfactory solution?  If so, great!

[IOSIFSTALIN2015]

NO MAN! i just fake it for example... thats what i need as result but offcourse not by hands in each frame...it must work by logick. 

In this situation - one helper must moving on path by camera - yep thanx  - easy to do by wire ...but at the same time helper must be free to hand made keys on his path.....if i just constraint helper to path and then wire this helper to camera its lock - impossible to hand made...how to deal with it?

[leeminardi]

I think it might be best to back up, forget about terms like linking, constraint, wire parameters, controllers and just simply state your requirements.

As far as I understand what you want to do is:

1. There are 3 objects, helper-1, helper-2 and camera.

2. Be able to click and move any one of the three objects along its specific path and the other two objects move along their respective paths.   

3. Be able to temporarily independently move a helper on its path without affecting the other objects.

[IOSIFSTALIN2015]

yes and a little bit no 

1. "There are 3 objects, helper-1, helper-2 and camera". - YES

2. "Be able to click and move any one of the three objects along its specific path and the other two objects move along their respective paths." - NO ...not any - CAMERA is first parent ...click and move camera and everything moves along their paths following camera - camera parent to helper-1 - helper-1 parent to helper-2. Camera moves = everything moves...And if you click-drag helper-1 it can moves along its own path  camera independent  and will move helper-2 but cant affect back to camera...if you click-drag helper-2 nobody move (just helper-2 move in space)

3. "Be able to temporarily independently move a helper on its path without affecting the other objects." NO -  be able  to temporarily independently move a helper-1 on its path WITH affecting helper-2 (helper-2 child of helper-1 and helper-2 havent path)...in this way helper-2 "feels"-receiving data only from helper-1.....and if you click and drag camera helper-1 moves and helper-2 moves (driving by helper-1).....every time you tuch camera - everything moves.....and if you tuch helper-1 only helper-1 moves and moving helper-2....if you tuch JUST helper-2 it can moves to in space . 

You drag-tuch camera = everything moves (camera on path>helper-1 on path>helper-2 linked in space to helper-1)

You drag-tuch helper-1 = only helper-1 moves on path and moving helper-2 in space

You drag-tuch helper-2 = only helper-2 moves in space

[leeminardi]

If you want the position of helper-1 on its path to be dependent of the position of the camera on its path then that relationship would need to be broken if you want to move helper-1 without affecting the position of the camera.

You could add a Transform Link Constraint when you want to be able to move helper-1 independently of the camera. For example, Dummy001 (large white square) has a path constraint to its path and Helper-1 (small green square) has a Transform link constraint to the dummy in frame 0 but linked  to the world in frame 27 and is therefore free to move independently.  So, from frames 0 -26 Helper-1 follows it path you move the camera along its path.  From frame 27 on helper-1 is free to move as you wish.

[IOSIFSTALIN2015]

ist it possible without broken? and green is big and white is small ..you say "Dummy001 (large white square)" - which one