Q:

Autodesk forge add geometry to model in browser

I am trying to create an online Revit viewer using Autodesk Forge APIs. The task I am trying to achieve is to be able to edit colors of existing geometry and also add new geometry to the model from the browser. Does anyone know how to do this, where I can get started, or if this is even possible?  

A:

Yes, you absolutely can edit colour and material of existing model geometry and aggregate models. I believe Philippe's gallery sample provides extensions that do both:
https://github.com/Developer-Autodesk/ng-gallery
If not, another of the GitHub samples does.
You should also check out the cloud and mobile DevBlog.
Here is a sample that edits materials within the Forge Viewer scene:
http://adndevblog.typepad.com/cloud_and_mobile/2016/08/ace-editor-for-threejs-shadermaterials-in-the-forge-viewer.html
Here is an article on adding Forge-translated OBJ models to a scene:
http://adndevblog.typepad.com/cloud_and_mobile/2016/08/loading-obj-files-translated-with-model-derivative-api-into-a-threejs-scene.html
Full model aggregation is discussed here:
http://adndevblog.typepad.com/cloud_and_mobile/2016/02/model-aggregation-with-view-data-api-exposed.html

