Clipping Plane to use from Geometries

Is there any easy way where we can use Clipping plane as Geometry.
I Cesium, I see terrain clamped into ground as Box geometry. But couldn't use that sample in 3D tileset sample. Any suggestions?

Can you describe a bit more about what you mean? If you’re just trying to create a visual plane that acts as a clipping plane, you can do that by creating a plane entity like in this example:

If this isn’t what you’re trying to do, can you link to an example, or a screenshot and describe a bit more about your application?

The clipping plane we see at top, which cuts tileset, I want to customize that clipping plane. So that I can clip only part of tileset.
Let's say I want to clip tileset using a square polygon, defined by lat lon coordinates. I want it to act as clipping plane.

see this link, Its a top down view of the example. See the red square box, I want to clip that part only.

Ah yes, thanks for the screenshot. That definitely helps a lot. You can do this by setting unionClippingRegions to true, see the docs here:

So instead of one plane, you would define 4 planes that cover the area you want. Here’s an example that applies this to tilesets:

Sandcastle example.

I couldn't run that sample, I just see slider on the page. Can you please check.
I went through code anyway, I'll have to run it to understand it better.

For highlighting we use create entity and give it as classification type as TERRAIN or BOTH. So it gets highlighted.
I wanted to do the same. Define polygon, click and move that up or down to clip tileset. I suppose we can move that up or down using some button control and event listener too right?

That’s concerning if that example isn’t running for you. What browser and OS are you using? Do you see any errors in the developer console? (In most browsers you can access that by right clicking on the page, clicking inspect element, and then clicking on the “console” tab).

Classification and clipping work slightly differently. With classification the intersection between the entity you create and the terrain/tileset will be highlighted. With clipping planes, whatever is behind is each plane is clipping. So depending on what exactly you’re trying to do it might be easier to achieve with one or the other. But yes, if you’re using an entity as classification, and you move it (perhaps using a callback property) that should work.

Also make sure to check out the invert classification example here, it might be useful to you as well:

I see Error : Error: timeout
    at makeError (dojo.js:106)
    at dojo.js:1641

But when I ran it couple of times, It works. I see clipping panes on aeroplane model.
But This is also takes center point as reference, and builds out Clipping plane around it.

You said, the I can use entity with callback property it can work as Clipping plane. Can you add it in above sample. Also if I want Horizontal clipping, I just set appropriate Z value right?

Yes, you should be able to define a normal and a distance to define a clipping plane in any direction, not just horizontal/vertical etc.

Try adding a clipping plane to an entity that moves with a callback property (here’s an example if you need a reference

If it doesn’t work, please provide a Sandcastle example (by clicking “share” and pasting the link here) and I’d be happy to take a look.