After reaching out for help on Volume Calculation, I found valuable assistance in this specific thread. Since then, I've developed a function that accurately calculates the volume of a closed mesh using Three JS. In my implementation, the variable face4 determines whether the face is divided into two triangles, specifically for Face3 meshes. The majority of my geometry involves custom Face4 construction.
function volumeCalc(object, face4){
if (face4 == false) {
for (var i=0; i<object.geometry.faces.length; i++) {
var pA = (object.geometry.faces[i].a);
var qA = (object.geometry.faces[i].b);
var rA = (object.geometry.faces[i].c);
// More calculations here...
}
} else {
for (var i=0; i<object.geometry.faces.length; i++) {
var pA = (object.geometry.faces[i].b);
var qA = (object.geometry.faces[i].c);
var rA = (object.geometry.faces[i].d);
// More calculations here...
}
}
// Additional calculations...
}This solution is based on the following formula:
pv = Px*Qy*Rz + Py*Qz*Rx + Pz*Qx*Ry - Px*Qz*Ry - Py*Qx*Rz - Pz*Qy*Rx;Prior to creating the mesh, I execute the following operations on THREE.Geometry:
geom.mergeVertices();
geom.computeCentroids();
geom.computeFaceNormals();
geom.computeVertexNormals();
// Subdivision modifier
var modifier = new THREE.SubdivisionModifier( x );
modifier.modify( geom );The volume calculation works accurately when x > 0 and subdivision is applied. However, discrepancies arise when x = 0 or there is no subdivision.
Any suggestions or insights on improving the function for broader usage would be greatly appreciated. This marks my initial endeavor towards open-source contribution. Thank you for your feedback.