Hi, I've been attempting to extract a volume calculation from two LAS files and have tried a few methods advised in this forum but I'm having limited success with final reported volumes being incorrect.

I have an existing level LAS file with a secondary as-built LAS file which I need to create a volume calculation and also generate a glb model solid. Method as follows:

1. Read 'existing' LAS and use TINGenerator to create surface to extract volume calc.

2. Read 'as-built' LAS and use TINGenerator to create surface to extract volume calc.

3. Compare difference of volume calcs.

This method works OK for comparing surface area difference but not the volumes. My design software shows that the TINVolumeCalculator creates wildly different values which I assume is operator error.

However my preferred method using design tools would typically follow this pattern...

1. create surface DTM from existing LAS file.

2. create surface DTM from as-built LAS file.

3. extrude as-built surface down to existing surface and generate DTM volume/report.

Is this simple approach even feasible using LAS & TINGenerator route? Many Thanks