merge - Vertices not merged (output from Kinect Fusion) -

i have major problem right now. using kinect fusion capture 3d scene , output .obj file.

the output of file looks this:

v 123 123 123
v 123 123 123
v 123 123 123
vn 321 321 321
vn 321 321 321
vn 321 321 321
f 1//1 2//2 3//3

where v vertice, vn normal, , f face. 3 vertices makes face, number of face exacely 1/3 number of vertices. problem output kinect doesnt merge vertices together. after import maya , merge them together, number of vertice , vertice normals somehow become different!

number of vertice after merge: 52837
number of vertice normal after merge: 299997
number of face after merge: 99999

how possible!? shouldn't each vertice have 1 vertice normal? why there more normal vertices? code wrote can work if follows structure. way not merge vertices together, may cause problems me in future.

hope can me t_t

that's expected behavior. imagine have 2 triangle making quad. unmerged, that's 6 vertices , 6 vertex normals. after merging have 4 vertices since vertices @ diagonal corners united. if merged mesh smoothed ( using normals > soften edge , example) shared vertices share vertex normals. if mesh faceted, still have 6 vertex normals though have 4 vertices. that's numbers coming from.

if original geometry clean face count remain same - bad geometry may include duplicate faces should eliminated merge, reducing vertex count.

you can artificially inflate vert normal count doing mesh > triangulate followed normals > harden edge. cause mesh appear faceted. if want smoothed normals (again normals > soften edge) should expect around 1 normal per vertex on average.