Measure Only the Visible Portion of an Element

[MiguelG97]

Description 📝

As requested per user, the pre-made measurement tools should support measuring the area, volume, or length of only the visible portion of an element, so that calculations reflect the current geometry after cuts or intersections, rather than the entire element.

Suggested solution 💡

No response

Alternative ⛕

No response

Additional context ☝️

No response

Validations ✅

• Read the docs.
• Check that there isn't already an issue that requests the same feature to avoid creating a duplicate.

[agviegas]

Right now measurements are not bound to specific objects, so checking whether any active clipping plane cuts an object and updating "their measures" dynamically is a rather opinionated implementation that might break the use of measurements for other users. What we can do is explain how something like that could be accomplished, so that anyone can create their own "dynamic measurement" component easily. The original post only asked about volume, so I'll address that:

1. Get the three.js geometry.
2. Subtract the clipping planes. For that, you can use our geometry engine boolean function. You can see it in action here. For the plane, you can create a huge three.js cube whose face is coplanar with it.
3. Once you have the cut three.js geometry, compute the volume using this logic. It's a very simple solution for computing the volume of arbitrary meshes.

Hope this helps!