steady points on curve

[Yassine]

Hi everyone,

I have a bunch of curves that wave with noise. These curves are smoothed and resampled few times, plus they stretch in length. The point number on the curves of course keeps changing over time and this cause very unstable motion blur in rendering.

How can I get steady point number on the curve?

Any suggestion is most welcomed

[Hudson]

Hi,

from the top of my Head I would add the motion after the operations on the curves (smooth, resample and so on). Would you be able to do that?

cheers

[Yassine]

Hey Hudson,

it seems like that the idea is to try to get a steady number of points before generating the final curve motion and deformation, and before you calculate the velocity. So then any smooth and resample steps wold interpolate with the original segmentation.

I'm wondering though if there is a possibility to stabilize whatever point segmentation you end up with afterwards..

[Hudson]

If I get you right the point segmentation is based on the length of the curve. So if you create a procedural way of calculation the new sample distance for the resample in order to obtain the same amount of points it should work. altough if you resample the curve at each, frame there still migth be some problems.

I would say that the problem occurs when you build your network like this ->motion(deforming the curves length) ->resample. If you do the contrary you can change the resample afterwards. altough the curves(and the distance of each point to another) will get stretched if they are deformed.

A hip-file or example would help what you want to achieve . I am getting a little confused

[Yassine]

Oh you got it right. As you said the way to go is to control the number of points resampled by defining the maximum number of edges before any sort of of stretching/deformation. And it works fine.

I guess I was trying to think of a case scenario where you might wont to get it to work when using a more adaptive resample method where the points are not the same amount at the first and last frame of the deformation.

I'll see if I can work on a test file eventually

[Hudson]

In that case I would buld up the same way as we mentioned and add the motion afterwards.

thereafter you can resample as you want as long as you transfer over the vel from animated curves. You could then have a pretty detailed curve(a lot of points) to cache de motion and vel. then just usa an attrib-transfer or do a point cloud(faster) solution to transfer the v-attr, I haven't tried but it should work