I’ve been working on a project, where its supposed to switch between multiple pointclouds.
That has been working nicely so far, my only problem is, that as it is in the state of morphing, it is dissolving in form of tiles (picture for reference).
I have been trying to find a way, to be able to automatically trigger the amplitude of a noise top, so that, as it is switching from one pointcloud to the next, it is dissolving, rather then forming these patches. I have tried to create a second lfo-count-filter-fan-null set up to controll the noise, but unfortunatly it didnt work.
you can solve this with a lookup into a sine curve created with a Pattern CHOP. Imagine adding a Noise TOP after each pointcloud and controlling the amplitude with the lookup.
You would want to adjust the Noise TOP a little. First set the Offset parameter to 0 for you to get a noise that is equally distributed in positive and negative space. Next also toggle off the Monochrome parameter in order to get noise for all 3 dimensions. Finally, and this is also important, set the Alpha parameter on the Output page to “Input”. For pointclouds the alpha channel is often used as a active channel indicating which points in the texture are actually used. Consider having a pointcloud with 7 points. Trying to save this into an image would require a image resolution of at least 2x4 pixels. So there is an extra pixel that is not part of the pointcloud. That is often where the alpha channel is used.
Anyways…
For the lookup create a sine curve with a Pattern CHOP and set the Phase parameter to 0.5. Also change the From Range parameters to -1 and 1 respectively in order to re-range the curve to a 0-1 value range. Now create a Loopup CHOP and use the output from your Fan CHOP as the first input into the Lookup. Plug the Pattern CHOP into the second input of the Lookup and set the Lookup’s Per Index Channel to “All Lookup Table Channels”. Now you have a channel for each Pointcloud’s Noise Ampltude which will take the amplitude to 1 during transition and back to 0 when the transition has concluded.
You might also like to plug the pointcloud into the second input of the Noise TOP. This returns Noise values from the 3D Noise field meaning it will not just look random but actually make spatially sense. Adjust the Noise’s Period and maybe even animate it on the Transform page a bit.