Forum

Spikes on a sphere

hello guys,

have to as some questions again.

actually it is about something that could help me on 2 similar problems.

what i want to do is, that i have a sphere. from the outer boundaries i want to raise some kind of spikes. Since i’d have to draw lines, it seems like i
need to work with a CircularSpread, or better two, in the same phase and different width/heigth. So far so good. This will work in a 2 dimensional room. But what about having it in 3d? is der any way to give some rotation to the spread?

what worked was to have a Rotation before the Translate Node which does the positioning inside the “room”. Since i want to be able to work with different amounts of spreads for each Sphere, I had to kill the Translate and Rotate and do the positioning on the X/Y Pin of the CircularSpread. Then i get in trouble when adding Rotate, because it will only move all Spheres/Spreads around the 0/0 of the renderer…

Thank you for your support!

I hope the patch attached is easier to understand than my description

rotation_with_circ_spreads.v4p (17.7 kB)

you can resample the 2 translate / rotate transformations in such a way that it fits the 14 translations from the circular spread, using GetMatrix (Transform) and SetMatrix (Transform) . take note of the binsize on the Resample (Spreads) node!

edit: second version also shows you how to use the Billboard (Transform) node to make the quads face the camera all the time.

you can resample the 2 translate / rotate transformations in such a way that it fits the 14 translations from the circular spread, using GetMatrix (Transform) and SetMatrix (Transform) . take note of the binsize on the Resample (Spreads) node!

edit: second version also shows you how to use the Billboard (Transform) node to make the quads face the camera all the time.

rot-circ-alt.v4p (10.9 kB)

some time ago i made a spikes on sphere patch, maybe it is what you are looking for:

some time ago i made a spikes on sphere patch, maybe it is what you are looking for:

sphere_spikes.v4p (19.3 kB)

Well, I used to say, use Cartesian and Polar for this stuff, but now we have a SphericalSpread (I think it is in the plugin pack).

edit: cool patch mr. Tonfilm :)

Well, I used to say, use Cartesian and Polar for this stuff, but now we have a SphericalSpread (I think it is in the plugin pack).

edit: cool patch mr. Tonfilm :)

SpikeSphere.v4p (12.4 kB)

yes, spherical spread is a very good idea, west…

@diki: you made my day… thank you for the introduction to Get/SetMatrix and the Resample node :D solved a lot of problems.

@tonfilm and west:
great input!

@all:

you guys are amazing!