The difference between Volume and Material:Volume

If you've tried creating Material Takeoff Schedules before you've probably noticed that there are two parameters to represent volume. The parameters may result in different volumes, so it can be unclear as to what they actually represent. I've had many users ask this, so I'd like to try to clear it up.

Volume is calculated based on the coarsest geometry of an element that has a volume. So for example, for a beam there is no physical geometry in Coarse detail, so its Volume is calculated based on Medium detail.

Material:Volume calculates the volume based on the element's geometry in Fine detail.

Comments

[Joel Osburn]

Clear, succinct definitions like this are what should be in the documentation...

Thanks for the post!

[Chad]

Users should take note of the inaccuracies and limitations that Material Takeoff Schedules have. They should be used with caution and users should always check the calculations.

If you have a Split Face and a Wall Sweep on a wall, and the Wall Sweep Material and the Wall Material are the same, the volume for the sweep does not increment the Wall's material volume.
Furthermore, if there is a Wall Sweep on the wall, then the Split Face material (different from Wall material) doesn't list in the schedule. When you delete the Wall Sweep, the Split Face material then shows up in schedule. This is not so important with Volumes as a Split Face has none, but is important for Areas.

Finally, the last thing you will notice is that the Split Face material area is not subtracted from the area of the material on the wall.

So the Material Takeoff Schedules should be used with extreme care, or preferably not at all as they don't yet work correctly.
It would have been nice to have important inaccuracy issues such as this fixed, rather than a new UI which does nothing for us.

[Andre]

Are the two volume calculation methods a feature (course and find volume) or a bug (sometimes one way and sometimes another)? The information is useful but I'm not sure if I should design workflows around it.