3D Multipatch not showing up in Web Scene

[DevRobinson]

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. 

[Koeller_Christine_A_-_DOT]

Okay, so multipatch surfaces won't work with Scene viewer they way 3D polygons can be added and displayed, they have to be converted into SLPKs? Is there documentation on this? E.g., these z-enabled polygon features can be opened in Scene Viewer, and display fine. I think the enhancement would be enabling this same functionality for multipatch feature layers: Airport Trans 57 Approach Surfaces - Overview. Spatial Reference is: 102974  (102974) 

[RussRoberts]

Correct, you will need to use a 3D layer https://doc.arcgis.com/en/arcgis-online/reference/scene-layers.htm

For surfaces you could also publish an elevation layer and use that in your scene 

https://doc.arcgis.com/en/arcgis-online/manage-data/publish-elevation-layers.htm

[Koeller_Christine_A_-_DOT]

This z-enabled polygon feature layer can be opened in Scene Viewer, and they display fine. I think the enhancement would be enabling this same functionality for multipatch feature layers: Airport Trans 57 Approach Surfaces - Overview. Spatial Reference is: 102974  (102974) 

I'm understanding that doesn't exist. You have to take extra steps to convert multipatch to a 3D layer? Is that how it's going to stay going forward?

[Koeller_Christine_A_-_DOT]

I'm also wondering if 3D object layers can be downloaded on open data sites, or would we keep this as a separate content item: Airport FAR Part 77 Surfaces | WisDOT Open Data - and I also always wondered why the multipatch features don't preview on the map in Hub. 

[RussRoberts]

Depending on the use of the layer you could provide the scene layer package or the multipatch gdb or sd file. You can also use a tool in Pro to export a scene layer package from a service but you cannot go from a package back to a multipatch. 

[RussRoberts]

Yup correct. displaying a multipatch feature layer in the web would no scale and be very expensive and is why we use the 3D layers for display. No steps to convert but at publish time you will see an associate scene layer being published along side the feature layer (this method will use credits to generate the scene layer in ArcGIS Online) or you can create it locally in Pro using create scene layer package tool. 

[Koeller_Christine_A_-_DOT]

Here's what my IT said about your response: "that is correct if we were publishing the feature as a scene. We are not, we are publishing the feature as a hosted feature layer."

This makes me think we need two separate content items, a hosted feature layer for the multipatch features that can be downloaded through our Hub site, and a second 3D layer if we want to visualize the features in scene. Our IT believes we have to publish these things separate. So now I'm confused again. Thank you for helping!

[RussRoberts]

These wont need to be published separately. If you have a scene in Pro with the multipatch being used when you go to share that scene as a web scene you will see in the sharing panel something similar to this. 

This will publish a hosted feature layer that could be used for export. Then you will have a scene layer that will have the cache built in ArcGIS Online as well and both layers are essentially published in one click. Or you could publish just the feature layer and then use the create scene layer package tool and then upload the package to ArcGIS Online and then you would have a proper 3D layer for visualizing that original multipatch in a web scene and also be able to bring it back into Pro or used in ArcGIS Earth.