Jump to content

Differential curve growth


none

Recommended Posts

Not sure what you mean, but just generally in regard to binding this kinda stuff to surfaces, doing extrusions or offsets, what I would do - and to make it work on any object - is remeshing the surfaces in the solver (slow as F, though, as it's a single threaded SOP) and then using the normal from the underlying surface (transfer it to the output from the solver, or inside the solver) to transform it off the surface, like using @P += normalize(@N) * some multiplier in a point wrangle... :)

Link to comment
Share on other sites

  • 4 weeks later...

Hi There,

I have been trying to do differential curve growth in a controlled manner where with one or more attractors I would like to constrain where the growth happens and how much it does. I am working at the architectural scale so each iteration is moved in the vertical axis to create an overall 3D form via vdbs. I have watched the Entagma tutorials and have been trying to adapt their attractor based logic in mesh growth to curve growth but I am quite new in Houdini and was not sucessful to do so... 

I was wondering if anyone has an idea on how to do that. I have attached the file.

 

Thank you!

 

L

180120_AD_DG[2DE]_00B.hipnc

Link to comment
Share on other sites

Looking at your file, I can think of several ways to do what you are looking for.  The one I like the best is to create forces, vectors which are added in to affect the spread of the points.  I put together an example of making your setup work their way around other meshes without going through them, I will probably fiddle with some more stuff with it.  I do really like this setup.

Similar setups to this can be done using volumes which act as resistance to growth through a density variable.  I will fiddle with one of those next, but I wanted to get you something that might give you some ideas quickly when I saw the post.

Adam Ferestad

180120_AD_DG[2DE]_00B-Avoid.hipnc

Edited by Adam Ferestad
Link to comment
Share on other sites

Yay!!! I did it.  This one I actually love and will likely use myself for some stuff I have been thinking about.  It uses a density volume to proportionally remove the travel distance at each stage, effectively making it stop progression in areas of high density.

Currently I have a clamp on the values, so it only removes, but if you remove that, it should be straightforward enough to tweak it so you can make break it down like this:

density = 0: no change

0 < density < 1: Progress is slowed

density = 1: no progress

density > 1: Reverses progress 

The reversal of progress might be tricky due to how I am calculating the travel direction, if there isn't travel, the vector ends up being the 0 vector, so you would need to get around the case where a stopped section begins to reverse.  I would probably write another attribute that only changes if the length of the vector is above a certain threshold, so if density > 1 it can use that if it has an invalid vector for the direction.

 

Adam Ferestad

180120_AD_DG[2DE]_00B-VolumeResist.hipnc

Link to comment
Share on other sites

  • 3 weeks later...
  • 2 months later...
On 12/10/2016 at 9:08 PM, Thomas Helzle said:

I somehow always wanted to achieve a thinner version of the coral growth and finally succeeded today after some hints in the comments on this video:

So I extended my old Entagma-based setup and replaced the resample node with a remesh and fiddled quite a long time with parameters but finally got it working - one major hint was to add some minimal noise to the points to get it out of the 2D plane.
To not have it paper thin I added a poly extrude and 2 subdivisions. Mantra was too slow for me so I once again exported to Thea Render:

CoralGrowth.jpg

Cheers,

Tom

Hey, love your set up! If you don't mind, any tips on where to introduce the noise? Inside the existing Point VOP, a new one, something like mountain/jitter node? Cheers!

  • Like 1
Link to comment
Share on other sites

9 hours ago, sb526 said:

Hey, love your set up! If you don't mind, any tips on where to introduce the noise? Inside the existing Point VOP, a new one, something like mountain/jitter node? Cheers!

Yeah, just put some very small random offset into the system before the solver so that the plane isn't perfectly flat anymore. IIRC that was enough to make the system leave the plane.

Cheers,

Tom

Link to comment
Share on other sites

  • 2 weeks later...

Hey all,

I'm trying a little experiment to see if I can combine differential growth with space colonization.   I think I've done a pretty good job using a volume as the food.  Each frame the wire eats some of the density volume around it, then I use the local density field as a multiplier on the movement, thus causing it to stop moving when it runs out of food.  Obviously I had to shoot a pyro volume at it when I got it working.  Still figuring out a few things with it and playing, but I figured Id share.

 

  • Like 3
Link to comment
Share on other sites

  • 5 months later...

Hey Folks,

Some more very nice Differential Growth vids I've come across;

from Peter Höhsl on Vimeo

 

 

from Jan Fischer on Vimeo.  Its 2yrs old, but still impressive.

Cheers!

  • Like 2
Link to comment
Share on other sites

  • 1 month later...
  • 4 weeks later...
  • 2 weeks later...
  • 4 months later...
On 10/12/2016 at 1:08 PM, Thomas Helzle said:

I somehow always wanted to achieve a thinner version of the coral growth and finally succeeded today after some hints in the comments on this video:

So I extended my old Entagma-based setup and replaced the resample node with a remesh and fiddled quite a long time with parameters but finally got it working - one major hint was to add some minimal noise to the points to get it out of the 2D plane.
To not have it paper thin I added a poly extrude and 2 subdivisions. Mantra was too slow for me so I once again exported to Thea Render:

CoralGrowth.jpg

Cheers,

Tom

Hey Tom, mind posting that file? Cheers!

Link to comment
Share on other sites

  • 1 month later...
  • 4 months later...
  • 5 weeks later...
  • 2 months later...
  • 1 month later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...