Converting portions of a unique shape into solid objects to get Volume Information from

Greetings to the Community,

I have another challenge that I need some assistance with please and thank you.

I do a form of architectural sandstone-like concrete, which I build formwork/molds for, and then fill it up in unique layers. I come up with custom designs that involve unique layers/striations in the final product. I have been finding SketchUp’s Volume calculating ability for solid objects immensely useful to tell me how much concrete I need for each layer. With “straight and square” walls this has been a fairly simple process, but I am currently working on a crazy curved structure, and am struggling with figuring out how to determine volumes for each one of my “layers/striations”.

Hopefully, through the series of attached images, it will make some sense what I am trying to do and someone has a solution that I can manage. :blush:

Image 1 – A rough simplistic concept of what I am doing

Image 2 – My pencil crayon sketch of the design

Image 3 - My design drawn into sketchup on a flat surface

Image 4 – The actual shape of the fireplace surround

Image 5 – My attempt at trying to determine the volume of the 2nd from the bottom layer of the fireplace surround after intersecting it with the model in image 4 and deleting the excess lines. However, the resulting shape/object does not have the top surface included, therefore is not a solid object, and I can not determine its volume.

Image 6 – is a simplistic representation of what I am trying to do to determine volumes

Image 7 – is the model showing my formwork that will be filled with the layers of concrete that I am trying to determine volumes for.

Would be immensely grateful if someone has some ideas to accomplish this.

Thank you kindly for your input, let me know if you require some clarification.


Lift Calculation Model.skp (1.2 MB)

I think this sounds like something solid tools could help with - although I’m sure there are some who can think outside the box even further.

If you make each layer of the the concrete its own solid group - I’ve just done one because I’m lazy.


hello. you could recreate this top surface with curviloft plugin.

Otherwise, instead of intersecting with model, you can use the native solid tools and intersect with it

see :
wall intersect



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You already have the solutions :slight_smile:


Bonus points for using Joint Push Pull to do multiple grouped faces at once!

Solid tools is really powerful , you could actually use that to check all the shapes your former is going to leave behind

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As always, I am absolutely floored by the speed and efficiency which you all “come to the rescue”.

Thank you to all of you!

I had used solid tools previously for something similar, and kinda forgot about it. even still, I am glad I asked, because I was using it inefficiently, and the examples provided here, showed me much more effective ways to accomplish my goals.


amazing that you were able to do them all at once like that…if I can figure out how to replicate this properly, that is an absolute time saver/game changer for me!

thank you so much!

Hi @mihai.s , I have been following your video, and have been able to do a couple sections, but then after a couple, my main object which I am to select as #2 solid group when using the solid tools Split tool, stops being a “solid” and therefore cannot be selected as my #2 “solid group”.

Any insight on that…
I have included the .skp with the issue in it.

Thank you kindly
Lift Calculation Model - not a solid any more.skp (3.2 MB)

For some reason it has failed to create a face on the bottom.

You could try scaling everything up x10 , then doing the splitting.

Once you’ve got everything cut out correct , scale it 0.1 to get it back to the correct scale

I simplified each curve first, so as not to have hundreds of edges that are 1 cm or less. Instead of several hundred edges, I work with about 48 per curve.
It works faster, and the results are similar.

Thanks, hopefully I can make that work.

I’m running short on time, there needs to be a Freelancing Gig Hire section of this website, similar to Fiverr, where I could hire solution providers to accomplish the solutions. :slight_smile:

You’re welcome!

It should be easier if you work with fewer edges, faster, and the result should be good.

Click in sequence on the scenes tabs of this SU file for ideas.

Striations volumes.skp (743.4 KB)

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Thanks for the thorough reply @jean_lemire_1 !
The assistance from this community has to be second to none. simply amazing!