Hello to everyone,
sorry for coming too late to this topic, i did not notice it so far... I am from 3d-io, Spotmask Developer, and i would like to write here some correct information about stuff you have problems with.
As first, the crap you get using Spotmask is because you are using the DEMO Verison. The DEMO Version has "Fragmentation" so all color blocks are fused and colors cropped.
The commercial version has no such limitations. It seems people simply does not read the "ReadMe" before downloading
Spotmask is of course perfect in all it output features, and delivers the highest precision results. In some aspects we have even evolved far beyond Vray and other renderers (for example the latest complex Curvature and Thickness passes, as well as advanced setting for WPP and UV passes). Our customers do not use it without reason for medical and scientific visualizations, as well as VFX studios (those who work with mental ray).
So, your topic explanations about how Spotmask is damaged are simply false.
What you can address is something else: Fusion has a bug, or missing feature, for UV-Pass (UV MAP 3D Texture composting filter). Different from NUKE, which anti alias the UV textures when you use UV MAP 3D Filter and produce perfect results, Fusion has a non smoothed, boxy, "none" texture filtering. This means your VFX with 3D UV Maps will look awful or almost unusable, compared to what NUKE delivers.
We have been writing to Eye back in days about it, but there was no feedback. This is for example something we could notify BlackMagic in order to repair it.
thanks
best regards
igor posavec
3d-plugin I 3d-io