3D slice

[PanamEric]

Hello,

Thank you to all those members on this forum that take time to help novice users like me.

I am drafting a personal project, where I have to level a badly slanted floor and want to calculate the volume of material required, however I can't figure out how to do this on Autocad 2017
I figured if I managed to create a 3Dsolid I would be able to use MASSPROP but I have not figured it out yet.
The area is 6m x 4m and the levels of each corners (clock wise direction) are
1 reference
2 -5cm
3 -24cm
4 -21cm
So I want to calculate how much material I need to level this off.

I tried making a 3D box and stretching the corners but it does not let me
I tried drafting the perimeter with lines with a Z value and I was able to draft it but I can't use the slice command to cut the box. Tried joining the inclined lines and also tried 3Dpolylines. None of these work with the slice command.
I know there must be a way to get this done but I have spent several hours googling this and I can't seem to find out how.

Is it possible to use a rectangular planar object that has different Z values in each corner as a slicing plane or any other way to achieve what I am trying to do?

Thank you

[Tom G]

It would help us if you share a file that shows what you have tried so far, able in the Full Editor & Preview button below a reply.

Do you want to add material to fill the floor and make it level, or do you want to remove material from the floor to produce a level surface?
Do you want something level, or something flat? These are easily confused and misspoken. I used to work on floors. I never asserted to produce level floors. I made flat floors. Level has to do with foundations, framing, and other building aspects which I have no control over.

You can use the Split command upon a Body with a Reference Geometry Plane as its cutting entity, to 'slice' through an object. You can then use Mass Properties on the resultant body to find what I understand you are looking for.

[DanPihlaja]

See the attached GIF video for how I would do it in Solidworks.

Click on the pic above to view the video.
Edit: The original video has been sacked, I replaced the video with a better resolution one.
Edit2: The previous video that sacked the original video, has been sacked. It has been replaced with a better resolution one.