AnimationCurve set tangent mode from script

Hello, I've been changing the tangent mode of an animation curve I have through script by using

Code (CSharp):

1. UnityEditor.AnimationUtility.SetKeyLeftTangentMode(difficultyRange, i, UnityEditor.AnimationUtility.TangentMode.Linear);

However, since this is a UnityEditor function I cannot use it in my build. There used to be

Code (CSharp):

1. keys[i].tangentMode

for each key, but thats deprecated and it tells me to use the Editor function which I cannot use as this is needed for the build.

Are there any other options I have to get this working? I just want to change the tangent mode of a keyframe from script.

 

Have the same problem.
One possibility would be to create the AnimationCurve in the inspector manually.
But as soon as you have to change it dynamically during runtime, this is not working anymore.

Did you find a solution?

 

Sadly I did not, but in my case I simply needed to have a straight line between two of the points in the curve instead of an actual curve, so I could just interpolate linearly between two values.

But apart from that I think it's just not possible sadly.

 

Same problem. I want to generate curve what should be X-pos of the camera, but curve always stay linear...

 

• Same problem, After two years, is the problem still unresolved?
  

 

FYI: We have the same issue here.

Any suggested workaround?

 

Sadly I still haven't found one

 

Reading API documentation can help
To modify a Keyframe tangent, you need to use KeyFrame.inTangent and outTangent.
However, there's a little trap: the keys of an AnimationCurve are not given to you by reference, but by value.
If you don't know what that means, it means that when you call AnimationCurve.keys, it gives you a copy of the actual keys rather than the keys itself. Any changes you try to push on that way will only affect the copy, not the original.
To fix that, you can copy the whole key struct locally and make changes there, then reassign the new key to the array.
Pseudocode example:

Code (CSharp):

1. AnimationCurve curve;
2. KeyFrame newKey = curve.keys[n]; //copy key we want to edit
3. newKey.inTangent = x; //change the tangents
4. newKey.outTangent = y; //change the tangents
5. curve.keys[n] = newKey; //reassign to the same place we copied earlier

The downside to this is that you will have to do some math to figure out where your tangents should be.
Alternatively you could look into using keyframe.inWeight, outWeight, and weightedMode, but I've never used those myself so can't readily tell you how to use them to achieve the desired effect. Experiment a bit.

 

To change the tangent mode of an animation curve through script you can use this code example:

Code (CSharp):

1.  
2.        AnimationCurve myCurve = new AnimationCurve(myKeyframes.ToArray());
3.  
4.         // Set here the keyframe tangents to Auto.
5.         for (int i = 0; i < myCurve.length; i++)
6.         {
7.             myCurve.SmoothTangents(i, 0);
8.         }

 

made this code

Code (CSharp):

1. for (int i = 0; i < curveAnimation.length; i++)
2. {
3.     Keyframe frame = curveAnimation[i];
4.     if (i > 0&& i != curveAnimation.length - 1)
5.     {
6.         var nextFrame=curveAnimation[i+1];
7.         var prefFrame=curveAnimation[i-1];
8.         float inTangent = (float) (((double) frame.value - (double) prefFrame.value) / ((double) frame.time - (double)  prefFrame.time ));
9.         float outTangent = (float) (((double) nextFrame.value - (double) frame.value) / ((double) nextFrame.time - (double)  frame.time ));
10.         frame.inTangent = inTangent;
11.         frame.outTangent = outTangent;
12.     }
13.     else
14.     {
15.         if (i == 0)
16.         {
17.             var nextFrame=curveAnimation[i+1];
18.             float outTangent = (float) (((double) nextFrame.value - (double) frame.value) / ((double) nextFrame.time - (double)  frame.time ));
19.             frame.outTangent = outTangent;
20.         }
21.         else if (i == curveAnimation.length - 1)
22.         {
23.             var prefFrame=curveAnimation[i-1];
24.             float inTangent = (float) (((double) frame.value - (double) prefFrame.value) / ((double) frame.time - (double)  prefFrame.time ));
25.             frame.inTangent = inTangent;
26.         }
27.     }
28.     keyframes.Add(frame);
29. }
30. curveAnimation.keys = keyframes.ToArray();

it makes every keyframe be linear