How do I translate 3D tiles and models?

I'm new to Cesium, and I want to make an in-browser landscaping application. I'd like to be able to stretch buildings, place trees, move sidewalks, that sort of thing... and have each change reflected in my database of assets (their positioning and scaling factors, etc.) It looks more to me like the maximum level of interactability allowed through Cesium is highlighting and showing tile model details, but you can't manipulate the models themselves. Or am I wrong?

You can absolutely manipulate the models themselves! You can even manipulate individual pieces of the model. I recently put together an example of programmatically rotating the wheels on a car here:

In addition to rotation, you can translate/stretch and scale in the same way. I remember there being a way to non-uniformly stretch the whole thing, but looks like this was not merged:

There also do exist some widgets built on top of CesiumJS for having a UI to do all these changes:

Creating models with the Primitive API might also give you more control, in terms of having access to the modelMatrix and individual nodes in your model:

Let me know if you have more specific questions or you get stuck trying to do something and I’d be happy to help.