Allowing polygons to drape vertically (or any direction) over 3dtilesets

[jinpark]

Hello,

I am trying to “drape” polygons over 3dtilesets. The idea is to be able to highlight distinct layers of the terrain in our tileset. The issue is the standard polygon entity looks ok when the polygon is mostly parallel to the ground, there are issues with the polygon not showing up as expected when the polygon is mostly vertical (ex. cliffs, caves).

I have an example sandcastle linked. The white polygon is mostly ok but you can see that the top left part of the polygon is hidden below the terrain.
The red polygon is mostly hidden due to the terrain and the heights of the polygon points.

sandcastle: Cesium Sandcastle

The points in the example have been created by using pickPosition.

What we want to do is allow users to create highlighted areas of the 3dtileset by clicking on the tilesets and creating an area. This area would be stored in the db and shown to other users later.

what we want it to look like

This is using a different software but it is able to create polygons that wrap horizontally around the terrain.

If there is another way to do this that I’ve missed, please let me know!

[anneg]

I have not much experience with that, but I found this related question: Image over Tileset

Which brought me to the classification. Click on the “highlight building face” in this Demo:

Cesium Sandcastle

Classification can work on terrain, cesium 3D tile and on both:

Cesium Sandcastle

I hope this helps!

[jinpark]

Thanks @anneg

The related question seems very similar to my problem.

I did look at the highlight building face sandcastle before and it seems like the way it was done in that example was to create a 3d rectangle and impose it onto the face of the wall.

While this would work for a simple vertical wall, i think it would be difficult for users to be able to create a 3d polygon to be able to “mark up” a specific surface, especially if the surface has a lot of bumps/indents (ex caves) and doesnt follow along a straight vertical or horizontal face.