How to get the volume information out of a mesh?

I am doing a project recently which requires me to get volume of different parts of pinnaes. The pinnaes are taken by digital camers and transfered to pointcloud .I can transfer the point cloud into 3D mesh. Now I have to find a way to get the volume of each parts,or find something to represent the volume.Professor suggested me to try filling the area with pixals and calculate the number of holes filled.How to do that? Now I have vertices,faces information and I have the stl file of the object. I tried some commands such as tetramesh,imfill,but got nothing valuable. Please help me. Since there is no way to put pictures here,I can just give the data. Just some hints,like how to put pixels into the 3D area and calculate the numbers of them.Thanks

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/7924-where-can-i-upload-images-and-files-for-use-on-matlab-answers

http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup#answer_18098

Answer 1

[Walter Roberson]

This contribution might help: http://www.mathworks.com/matlabcentral/fileexchange/15221-triangulationvolume

When I go back through discussions, I see that the recommendation is usually to convert the mesh to tetrahedrons and then to sum the volumes of each of the tetrahedrons. There is a contribution to do the conversion to tetrahedrons at http://www.mathworks.com/matlabcentral/fileexchange/27830-mesh2tetra