Compute materials has holes in the results

[arnar_stefansson]

Hi,

When I use compute materials så calculate material with more than 2 criteria surfaces, there are always some random sections that only show results where all the criteria surfaces apply. 

I have a road surface and existing ground, plus a new surface which is a filling for constructions within an area between new read and existing ground. I want to calculate the volume for this filling in one step. I would have thought that it would be enough to use the new surface as below criteria and the other two as the above criteria. Some of the sections show the correct result, others are only showing data where both above surfaces apply. 

I know there is a way around this, but what I am wondering about is whether I am using this 3 critieral feature the wrong way (and in fact, the results should only be showing where all three surfaces apply) or if there som someone who knows what is causing this inconsistency in the results. 

Best regards,

[ecfernandez]

Hi @arnar_stefansson, according to your explanation, I'd advise you to check the criteria. When you say "above" or "below," what you are telling Civil 3D is where the material will be located regarding the specific surface you are setting that property in. Make sure you covered all the scenarios into the quantity takeoff criteria, and it will certainly work.

Check this video: https://www.youtube.com/watch?v=mz6q_vHysbE&t=332s&ab_channel=JeffBartels 

I hope this helps. Best regards!