Creating complex solid geometry in SketchUp 2020

Hi SketchUp Community,

I am a newbie in SketchUp Pro 2020 and I try to create 3D solid object from 2D CAD drawings. This object has complex surfaces and geometries and I have so many troubles with that one. I use a point cloud and 2D drawings aligned togehter as a template for creating 3D model. The image of point cloud of the object is below:

Now I created the top surface and I need to pull the geomtery below (both sides):

When drawing a rectangle as a base, this method does not work at all. I have no idea how to start doing this part well.

I will be so grateful for any advice for this project. Maybe is something I need to change sth or make some part differently.

Thank you so mych in advance.


Hi Jakub,

You are trying to do what is commonly referred to as “reverse engineering” a part, and it is, unfortunately, a complex way to work in any CAD system. Methods vary, but in SketchUp what you need to do is to identify the major geometric forms in this part and model them one at a time. Do you have access to the physical part as well as the drawings and point cloud?


Hi John,

I have access only to data (not physical part). Basicly I created the top surface this object but I have no idea how to make a solid below. I insert a rectangle containing this outline inside but this geometry is not taken into account as the clipping path (to pull sides). How to make a outline correctly to create it as a solid object?

I would probably tru TT’s Vertex Tools and SubD for this. It’s a quite tricky geometry.

Can you upload the outline you show, as a 3D SketchUp or .dwg file? Or the model itself, which you showed in your first image?

I’ve opened the file, and find it puzzling.

You have the default tag set to Powierzchnia - what does that mean? I guess it’s in Polish. Seems to mean ‘Surface’.

You should always leave the pencil showing the default tag set at Untagged (Layer0 in older versions of SU).

There’s a lot of stray loose geometry in the model, some distance from the origin, and not apparently part of your model. I’ve deleted it.

Some geometry only shows when I double click on the group that contains it - not sure why. Turning on View Hidden Geometry and View Hidden Objects doesn’t on its own make it visible, nor does turning on all the tags.

I moved the visible geometry to the origin. It’s left behind what I think is an outline of the faces you’ve created showing as C-points and looking like this:

You have two similar but not identical side profiles in your model. Which is the original CAD drawing one?

You have View/Shadows turned on, which isn’t helpful for this model, normally only used for Architectural models.

I think if I were you, I’d start again.

See if you can upload just the original CAD files in dwg format, and if possible, an image of the whole part if you have one.

Then let’s have another go at trying to model it from scratch (the beginning).

Thank you all for any supports. John, your tips were very helpful to me. Thank you very much for your commitment.

Using in the program such plugins as:

  • Weld,
  • Soap Skin & Bubble,
  • Point Cloud Importers,
  • Tools on Surface,
  • JointPushPull,
  • Curviloft,
  • Extrude Tools,
  • Bezier Tool,

it finally worked!

I now see what the solid shape is supposed to look like, which I couldn’t quite work out before.

Glad you have a result.

What is it? Or at least, what is it for?