surface area calculation

[ya]

I am calculating surface area of a collection chunk.model.faces as follows:

    vertices = [chunk.model.vertices[vertex] for vertex in face.vertices]
    v_coords = np.array([(v.coord) for v in vertices]) # no projection
    a, b, c = v_coords
    ab = b - a
    ac = c - a
    cross_product = np.cross(ab, ac)
    face_area = 0.5 * np.linalg.norm(cross_product)
    return face_area

am i correct in assuming the units are in (m^2) by default and no further transformations are required?

[Paulo]

Hello ya,

the area A of the sum of faces is in the units of the internal coordinate system. To get area Aw in real world units (m2) you must multiply by square of chunk transform scale as :

Code: [Select]

Aw = A * s * s
where s = Metashape.app.document.chunk.transform.scale

[Alexey Pasumansky]

Hello ya,

If your model is referenced you can compare your calculations with model.area() call result.