EDIT: Response can be found on odforce https://forums.odforce.net/topic/42883-mix-vdbs-with-different-densities-and-colours-in-houdini/ [forums.odforce.net]

Hello I have already posted this question on odforce but haven't had any responses so hopefully someone can still help me out please!

I am trying to mix/combine the density and colour of two different VDBs into one VDB in Houdini (image 1, file attached). For the most part, this is working as desired but there are two main issues:

1. Pink fuzzy edges around the blue VDB - How do I get nice clean edges where the blue VDB smoothly fades out to transparent? (image 2)

2. Blue VDB does not go all the way to the border of the pink VDB - How do I make sure both VDBs finish on the same outside border? (image 3)

I have tried adjusting the voxel size, changing the set up of the VDBs (ie. the exterior/interior band voxels, fill interior) but I can't seem to get it working the way I want.

Can anyone please help me? I have only been learning Houdini for just over a month so example files would be helpful. Thank you!