My issue is kind of a double problem I'm having with ArcGIS Online's Web Scene viewer.
Firstly, it never lets me add a ground surface because I refuse to use the WGS coordinate system, I need state plane! So I am never able to have a 3D ground surface to view my 3D multipatches with. THIS IS A DUMB THING TO LIMIT, ESRI!
So I figured I would cheat and make a multipatch surface of my state's ground surface using a DEM, which worked fine. Where I'm pulling my hair out is trying to get it to show up in my web scene!
I upload the .slpk file I exported from ArcGIS Pro and loaded it into my content on ArcOnline, and then added it to my established web scene. And nothing happens! It says it's there, says it's loaded, but no multipatch surface anywhere! All of my other multipatch features show up just fine and in the coordinate system I want.
I checked EVERYTHING, and I mean everything. Transparency, color, it's just not showing up. And no, it's not because it's too big. I made sure it wasn't a crazy resolution. And it's not giving a load error or anything. And besides, an even bigger set of multipatch surfaces I have is able to load in just fine, so I am at a loss as to why this one is just being gas lit by ArcOnline.
And the file is there, I can download it from ArcOnline and load it back in ArcPro just fine, but it will not show up in my scene!
Somebody please help me explain why, especially Esri themselves. I am ripping my hair out over this.