How to calculate 3D objects’ volume?

[JamesGregory]

Hello to all! Would someone tell me how i can calculate the volume of 3D objects plz? Thanks a lot.

[daniel]

really 3D or 2.5D?

Anyway, there are basically two options that may work for you:
- https://www.cloudcompare.org/doc/wiki/i ... ure_volume
- https://www.cloudcompare.org/doc/wiki/i ... .5D_Volume

[DA523]

Sorry I deleted this post by mistake ...while posting a new one
how to recover it

[DA523]

Lets speak about 2.5D volume (Tools >> VOLUME >>Compute 2.5D volume)

https://www.cloudcompare.org/doc/wiki/i ... .5D_Volume

it is the most professional method to find volume between 2 points clouds and works fine on 2 points clouds or single cloud and plane (constant x,y, or z)
it is the same as finding the area under function curve by numerical integration

Care should be taken because , it can give bad volume in some situations because of :
- Convex hull area if interpolation is used
- Empty cells, if the less dense points cloud is used with leave it empty choice
- Big grid size (too many points fail in each cell)
- One points cloud has more than one layer in the same projection direction
For example, 2.5D volume can not work on this attached mesh

Attached 1 bin file

2.5D volume.zip

(2.14 KiB) Downloaded 1193 times

[geotyr]

so I needed to compute a 3d volume for a surface that is not fit to the 2.5 volume computation (more than 1 points with the same x and y coordinates and different Z)

what I did is subsample the cloud points
compute normals
and then compute poisson reconstruction with the drichlet algorithm
this creates a closed volume
inverting the normals allows closing the surface in one direction or the other

it does not work for precise calculations but helps with general idea

depending on how normals are calculated affects how the surface is closed

[DA523]

Be careful about mesh volume you may have non-manifold and normal problem
you have to cross check using meshlab and blender to double check CC volume