# What's the algorithm used in bm.calc_volume()?

I need to know which algorithm is used in bm.calc_volume() (https://docs.blender.org/api/blender_python_api_2_67_release/bmesh.types.html#bmesh.types.BMesh.calc_volume) or which theorem is based on. It only says it's based on face normals and I haven't been able to find more information.

It would be also useful if someone could help me to find its code.

• This might help. On page two: chenlab.ece.cornell.edu/Publication/Cha/icip01_Cha.pdf
– yann
Sep 10 '17 at 15:03
• Thank you! But do you know if this is the one that Blender uses? Sep 10 '17 at 16:20
• No, i don't know that, sorry
– yann
Sep 10 '17 at 17:19
• search for BM_mesh_calc_volume on bmesh source code Sep 12 '17 at 12:56
• Uses the method outlined in link given by @yann .Tessellates the faces, then sums the tetrahedrons. Sep 13 '17 at 9:22