Hi all ,
In the help for the volumesmoothsample vex function, there are two images that show interpolated fields based on a series of known positions. I was hoping to extrapolate this to generating a heightfield via a wrangle where the sample points are fed into the second input. What trips me up is that I would expect it to need multiple input points to find the weighting and 2d position to sample from but you're always sampling a known P + an offset because you don't want to same @P directly otherwise you'll return the heighfields value at that location.
Volumesmoothsample
1488 5 0-
- zampha
- Member
- 10 posts
- Joined: 5月 2016
- Offline
-
- animatrix_
- Member
- 4616 posts
- Joined: 2月 2012
- Offline
Hi,
The smooth interpolation is used to interpolate between the voxels when sampling a single position, not to interpolate between multiple arbitrary positions from the field.
The smooth interpolation is used to interpolate between the voxels when sampling a single position, not to interpolate between multiple arbitrary positions from the field.
Senior FX TD @ Industrial Light & Magic
Get to the NEXT level in Houdini & VEX with Pragmatic VEX! [www.pragmatic-vfx.com]
![](http://imgur.com/fY0VxdV.png)
youtube.com/@pragmaticvfx | patreon.com/animatrix | pragmaticvfx.gumroad.com
Get to the NEXT level in Houdini & VEX with Pragmatic VEX! [www.pragmatic-vfx.com]
![](http://imgur.com/fY0VxdV.png)
youtube.com/@pragmaticvfx | patreon.com/animatrix | pragmaticvfx.gumroad.com
-
- jsmack
- Member
- 7981 posts
- Joined: 9月 2011
- Offline
-
- zampha
- Member
- 10 posts
- Joined: 5月 2016
- Offline
Many thanks for the reply. Fortunately I'm working through your excellent Pragmatic VEX series as I thought it might be the case, that it wasn't going to work; so my guess is I will be looking to extrapolate point based interpolation from 1D to 2D so I'll need four reference sample points rather than two. I don't suppose you would have any tips for getting started on that please ?
![](/static/djangobb_forum/img/smilies/smile.png)
-
- animatrix_
- Member
- 4616 posts
- Joined: 2月 2012
- Offline
zampha
Many thanks for the reply. Fortunately I'm working through your excellent Pragmatic VEX series as I thought it might be the case, that it wasn't going to work; so my guess is I will be looking to extrapolate point based interpolation from 1D to 2D so I'll need four reference sample points rather than two. I don't suppose you would have any tips for getting started on that please ?
Thanks a lot for your words
![](/static/djangobb_forum/img/smilies/smile.png)
https://www.sidefx.com/docs/houdini/vex/functions/spline.html [www.sidefx.com]
It supports various interpolations like linear, cubic (Catmull-Rom), K-Spline, Bezier/B-Spline/Hermite. I will probably cover these in Volume 2.
jsmack
I'm sorry, smoothsample? did they add some cubic or catmull thing for volume sampling?
https://www.sidefx.com/docs/houdini/vex/functions/volumesmoothsample.html [www.sidefx.com]
https://www.sidefx.com/docs/houdini/vex/functions/volumecubicsample.html [www.sidefx.com]
https://www.sidefx.com/docs/houdini/vex/functions/volumesmoothsamplev.html [www.sidefx.com]
https://www.sidefx.com/docs/houdini/vex/functions/volumecubicsamplev.html [www.sidefx.com]
Senior FX TD @ Industrial Light & Magic
Get to the NEXT level in Houdini & VEX with Pragmatic VEX! [www.pragmatic-vfx.com]
![](http://imgur.com/fY0VxdV.png)
youtube.com/@pragmaticvfx | patreon.com/animatrix | pragmaticvfx.gumroad.com
Get to the NEXT level in Houdini & VEX with Pragmatic VEX! [www.pragmatic-vfx.com]
![](http://imgur.com/fY0VxdV.png)
youtube.com/@pragmaticvfx | patreon.com/animatrix | pragmaticvfx.gumroad.com
-
- zampha
- Member
- 10 posts
- Joined: 5月 2016
- Offline
-
- Quick Links