Always point to one object

Artwork Compositions and effects
1

This file shows how to create an object that always points to other one:pointtome.sifz (1.05 KB)
-G

2

ah! =D something new to test, this remind me of that old example of an eye looking at some object, this combined with following a path would make interesting objects, i have to try it later, a little Off-topic; i installed via .deb package the recent build of Synfig, i must say thank you because everything works better for me, excellent implementation of the re-size/move/rotate tool, but overal, the excelent way in that .svg files are imported, even native Inkscape SVG files are imported without problems, nor even a window or something asking thins, and groups in Inkscape projects actually become ‘Encapsulate’ layers, great job G. i really like and enjoy the way in that Synfig is working, is really hard to think how to ask for more XD. keep ot up

3

Really cool technique Genete! I can see it can be very useful!
(How about a tutorial? :wink: )

4

Yeah, It could be a good tutorial.
Do you want me to do it or do you prefer to write by yourself?
-G

5

I can do it. :slight_smile:

6

I finally did the tutorial by myself. I hope you like it and don’t get angry with me :blush: :unamused:
-G

7

Here is the tutorial:
wiki.synfig.org/wiki/Doc:Point_to_one_object
-G

8

stumbled on this old thread by mistake and just wanted to add that there’s now a much easier way to achieve same goal:

  1. export the eye group origin as “eye.location”, and fly group origin as “fly.location”
  2. add a “rotation” layer to your eye group,
  3. convert it’s amount (angle) to “vector angle” and then convert this vector to “subtract”.
  4. link LHS to “fly.location” and THS to “eye.location”.

you can now freely move both the eye and the fly… and keep a close watch on the pest :wink:
(attached sample with crapy fly)

hope this helps.
B.
watch the fly.gif
watch the fly.sifz (2.17 KB)

9

by ‘‘now’’ you mean with the 0.65dev version ?

(I have added your notes in the wiki.synfig.org/wiki/Doc:Point_to_one_object talk page)

10

no, no, both “vector angle” & “subtract” have been around for quite some time in stable releases, and definitely readily are in 0.64.1.

Thanks for the wiki update. I added some illustration to make the maths accessible for all… you can even play with them directly.
wiki.synfig.org/wiki/Doc_talk:Po … one_object

B.

11

wiki.synfig.org/wiki/Doc:Point_to_one_object : Updated ! Fill free to alter it again …

Great initiative the math illustration !

12

That’s cool, but it won’t work if the fly is inside the eye.
-G