Homogeneous following does not work!?

Hey guys, my first post!

Thanks for the wonderful application you are creating!

I guess I don’t get something, but I don’t see any difference in arrow movement speed if I set the homogeneous parameter of curve which must be followed on or off!

If the blinepoints are homogeneously placed along the bline the result is very similar. Try to make some bline segments to be larger than the others and you’ll see the difference.

Again, I might be missing something, but there is no difference from switching homogeneous on or of on the path which is followed(arrow is moving very fast and then on the part with a lot of vertices is slowing down considerably)

Please see attachement, I slightly modified example from tutorials(added bunch of new vertices)
Arrow-follows-bline.sifz (4.19 KB)

Absurd answer :
Is it really homogeneous you want to use ?
—> wiki.synfig.org/wiki/Outline_Layer#Homogeneous <—
or the powerful waypoints ?
—> wiki.synfig.org/wiki/Waypoints <----


If I open your file I can see clearly the differences.

Please check the attached file where I did the following:

  1. Export the homogeneous parameter so it is linked in the rotation and the position.
  2. Remove the Offset animation for the rotation. It is not needed to compare the effect.
  3. Add 5 seconds more to the animation. It is 10 seconds length now
  4. Duplicate the animation of the amount parameter from the BLine Link convert type so now it has two cycles: from 0s to 5s (forward and backward) and form 5s to 10s (forward and backward again)
  5. Modify the interpolation of the amount parameter animation to make it linear in all its waypoints.
  6. Animate the homogeneous parameter so it is ‘off’ from 0s to 5s and ‘on’ from 5s to 10s.

So amount parameter animation is this:
from 0s to 2s linear from 0.0 to 1.0
from 2s to 3s linear from 1.0 to 1.0
from 3s to 5s linear from 1.0 to 0.0
from 5s to 7s linear from 0.0 to 1.0
from 7s to 8s linear from 1.0 to 1.0
from 8s to 10s linear from 1.0 to 0.0

And the homogeneous parameter is:
from 0s to 5s constant equal to ‘off’
from 5s to 10s constant equal to ‘on’

So, notice that at 1s and at 6s the amount parameter value is 0.5. A value of 0.5 means half the way but it has different effects depending on the homogeneous parameter:
0.5 is half the way of the index of the bline if it is not homogeneous.
0.5 is half the length of the bline regardless the number of blinepoints.

Arrow-follows-bline-homogeneous.sifz (4.15 KB)

Thanks got it! Sorry for nooby questions! :slight_smile:

The thing that helped me to understand problem and solution was that you exported homogeneous value from origin and rotation of an arrow, I was looking all the time at the wrong homogeneous value.

Don’t want to be pretentious, but it would be nice feature, if exported values could be located not only by their names, but also would have reference to the object from which they are exported!

But anyway thanks for spending your time, appreciate it much! :wink:

Exported value nodes are precisely independent from the object they derive from. Even you can delete the object it was obtained from and the exported value node would continue living. Exported value nodes belongs to the canvas (file) where they live in. Any value can be linked to it or disconnected from it. That won’t affect the exported value node.
You only can un-Export the value node to make it disappear form the Children panel and so only whom was linked to it, would hold an “unnamed” copy of the value node. That’s what happen when you link two values. They share the same value node but it is not exported, although it is still unique and still belonging to the canvas it was created in.


mm… interesting, I had a suspicion that something like this might serve as a reason, for not including reference, thanks for the info!

Will try to manage my schedule to have at least a bit of time to learn more about this amazing software. Synfig has such a potential! If everything goes well with the opengl rendering subsystem rewriting, also there could be user interface improvements and bugs which make application occasionally crash would be eliminated, then Synfig studio has such a potential!!! Few quality movies done and “World domination” here we come! :smiley:

More precisely Cairo rendering not OpenGL :slight_smile: