Where to make a 3D zoning application?

[MicahTaylor]

Does anyone know of a way I can make an application where the user can input basic zoning parameters to a zone type...and generate a simple massing on a map using parcel data.  This would be similar to CityEngine functionality but less detailed and consumable by an end user.  For example...

User inputs front setback, rear setback, height limit, and use...and a simple 3D building massing generates on the 3D map (perhaps generated onto an ArcGIS online Scene that is being used in the app)

The reason I ask is because a company has pitched an application that does this very thing at my job.  I think it is a useful app, but I feel like I should be able to build this myself with parcel data, CGA rules, and ArcGIS online Scenes.  Is there a 3D Api that lets me generate models within an existing scene?  or do the models have to be completely built inside of CE or ArcPro and then exported as static (non-editable) models every time a change is made?

I am thinking of something that works like a site-suitability GIS web application, but with geometry changes instead of raster changes.3DWeb GIShttps://community.esri.com/groups/3d-mapping?sr=search&searchId=d856ca4b-ee5b-4fb1-af10-7bdeb96e4b13... https://community.esri.com/groups/planning-and-design?sr=search&searchId=7e732a5e-6a91-4eb1-9a7f-d68...‌

Thank you in advance for your suggestions, thoughts, or comments.

[DavidWasserman]

This is the exact type of application that procedural as a service would benefit from, but as far as I know our only options for procedural rules are static model displays. I am not even sure how to make sliders for example be exposed in either the CityEngine web scene or ArcGIS Pro scene environment. As far as I know, procedural outputs must be "baked" before being shared. I was hoping for something like this for a temporal visualization and had to settle for "binning" the data into hourly segments. 

Theoretically you could emulate this type of behavior if all the model combinations were made before hand. I think for example you could create a range of zoning parameters in a jython script, and then use the itertools.product() function to product every feasible combination of those rule parameters, and then call those models based on a match from a users edits to that parcel...this however is not efficient and I don't even want to think about how many SPKs that would require. There are really no great solutions for interactive procedural editing over the web with a pure CityEngine/Esri stack yet. This might change or my understanding is out of date, and some one else could provide more input. 

What is the company out of curiosity?