This question came up today and I was not sure if I had ever covered it in a written form before so I thought I would capture the response here.
The question relates to how can you use SKP 3D Solid Models in TBC for visualization purposes etc.
So in TBC you have a couple of options that may help here
Option 1
When you place a block in the plan view to represent a feature point like a Fire Hydrant or Light Pole you can look at the properties of the Block and you can add a SKP file as a reference on the Block and the SKP is rendered fully as a solid in the 3D view.
You have to however make sure that your SKP file has its center point at 0,0 (and Sketchup has a weird way of handling origins they often use a corner of the object so if a circle it would be e.g. lower left corner of a square the size of the circle is the origin point which means when you place the object at the block location it is always going to be offset and in the wrong place - if you can create the SKP object so that its center is at 0,0,0 then it will place correctly in TBC. The SKP rotation is also important - make sure that the object Axis that you will use for rotations is either N-S or E-W so that it is easy to rotate them to align with what you are aligning the objects to.
This same approach can be used for the visualization of Utility Node Objects in TBC - you can create the node type and apply a Block that will be used to represent the object in the plan view. That block once placed can be substituted in 3D view for a SKP model object in the same way.
Note that when you define your Blocks - if you define them as a 2 Point Block then you can place your block at an Insert Point and rotate it using a rotation grip control. This makes it easier to rotate your blocks to the correct alignment in TBC once they are placed.
Note also if you use the Place Aligned Blocks Command (RPS Command) in TBC then you can auto compute the rotations of he blocks to be at a defined angle to a selected reference line or alignment and then substitute those blocks for your Sketchup model objects for 3D presentations etc.
The Video shows you how - I have been meaning to purchase a Sketchup License for a while now, so used this as a reason to do so - I will look into the shifting of the objects in Sketchup to work out a process for that from downloaded warehouse objects and will post a follow on video that covers that once I have worked it out - I used Sketchup a lot when Trimble was buying the company from Google (I was involved in the acquisition at that time) but really have not been involved that much with it since - I know a decent number of people that do use it with TBC and that is a good reason for us to start working with it again I guess.
Hope that this helps