Measuring area inside a closed curve on a mesh (PLY/STL) – am I missing something?

[[an...]]

Hello everyone! Andrea from Italy here, currently going a bit crazy trying to measure the area of a mesh

I’ll give you some context:
I’m working on a scientific study on oral wound healing. We use an intraoral scanner to compare two different surgical techniques, evaluating how quickly the wound closes over time.

The workflow is: scan patients at different postoperative time points, identify the wound area on each scan, measure the area and track how it changes over time

The scanner exports STL, PLY and OBJ files. I usually work with PLY because the color information helps me better identify the margins. However, I’ve tried all three formats and the issue persists, so I don’t think the file type is the problem.

What i'm doing:

• Import the mesh into Zeiss Inspect
• Draw a closed curve around the wound area on the mesh
• Try to calculate the area inside that curve

The Problem: I cannot find any tool that lets me measure the surface area enclosed by the curve. The curve is definitely closed, the mesh should be closed as well (no visible holes), I’ve looked through the available measurement tools but can’t find a way to compute the area within the boundary. As a comparison, I tried the same workflow in MeshLab, and it works there without issues. I'll add a screenshot of what i've to measure, i can provide you more screenshots etc etc....

I’d really prefer to stay in Zeiss Inspect since I’m already using it for additional 3D and vertical analyses, and it would be ideal to keep everything in one software.

Is there a way in Zeiss Inspect to calculate the area enclosed by a curve drawn on a mesh?
Am I missing a specific function or workflow?

Thanks in advance to anyone who can point me in the right direction, i'm sure i'm missing some stupid passages....

[[DW...]]

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 This is a different approach. Go to Construct>Surface>Smoothed Surface from Mesh then use the "Select/Deselect On Surface" tool to lasso the area of interest. Go to the I-Inspect and check "Area". This should give you what you need. 

[[TI...]]

Didn't expect to log into the forums and see some mouth wounds, lol.  Interesting what Zeiss Inspect is being used for, I'm in my own little bubble measuring titanium parts.

 

 

[[Na...]]

Hi Andrea,

the area on curves can only be checked directly, if they are projected into a plane. 

Here, you need to create a surface enclosed by the curve first, and then check this surface. I guess MeshLab does this in the background somehow. 

Workflow:

• create curve
• Construct Fitting Polynom Surface with all points of curve selected:
  • 
• Triangulate Geometrical Element from fitting polygon surface
  • 
• the resulting Surface (triangulated) can then be checked for area directly. Because the polynom surface needs some parameters to be defined, a direct check for area on a 3D curve would be ambiguous and that's why it's probably not available directly. 
  • 
• To make this evaluation quicker, click on the curve you created first, then chose from the menu Inspection -> Define User-Defined Inspection Principle. For the next evaluation you only need to construct the curve and click the little guy Icon like you would with a measuring principle. The elements and checks depending on the curve will then be created with one click (needs a Professional license):
  • 

There are some deviations because there is a fitting element included but it should give a comparable value for the wound healing process. Otherwise the curve needs to be projected into a defined plane to check for area, maybe the coordinate system of an implant could be used, if there is one available.

 

Nanno