So have been working on a vellum paper sim on a bunch (+50) shots. Everything was going well until one specific scene where the sim breaks. As you can see I am getting "tenting" and garbled pieces everywhere.
Overview: So I am using a scatter, popnet, copy to points , vellum constraints, then feeding into the vellum solver (SOP), applying wind, drag and noise etc. It is a very simple set up. Suddenly on a new shot with different positions (more on that later) on the assets (collision objects etc) I started getting artifacts so I deleted everything and copied a set up from a working scene. I tested the working scene and the new scene side by side with the same source for the paper notes (from lookdev): but the new scene was still broken. Then I took the working scene and "saved as" into the folder of the broken shot, and just replaced the emitter plane, same thing: broken. The funny thing is that if I used the old emitter plane, it works, but as soon as I animated it to match the shot it breaks again. I repeated this a bunch of times with no luck. The only difference that I could see between the working scene and the broken scene was the position of the assets. In the working scene they are about 50 units from the origin at a scale of 0.01, but for the broken scene they are 650 units from the origin (after scaling down by 0.01). Of course I tried to transform the whole scene with a null to the orgin to test but that didn't work either. Has anyone ever had a similar issue?
I don't really know what I'm looking at So it's difficult to imagine what issues you are facing and what broken means vs not broken in your case
But maybe try deleting all attributes before vellum nodes, since you are saying you copied on particles It's important to delete attributes liek i@id, since they may interfere with vellum
However if you are saying it works for other shots using the same setup this may not be the issue
sorry, here is what it is suppposed to look like (I posted the wrong pic above). I will try deleting the attributes too, but it is strange that it has been working without issue for months. The only difference I can see is the distance from the orgin in the new shot.
pskaifa Of course I tried to transform the whole scene with a null to the orgin to test but that didn't work either. Has anyone ever had a similar issue?
if it's a precision issue this would not help as the computation is done in object space so transforming that object with a parent null or its own transform is a post-operation
you can try transforming the geo itself closer to origin, with Transform SOP inside of the object for all inputs of the Vellum Solver
or alternatively you can try casting P attribute on all of your Vellum Solver inputs to 64bit I however don't know if Vellum Solver can take advantage of it, so its a long shot
