Triming / Splitting Model ~HELP~


I’m a newbie for Sketchup. I have downloaded a 3D model from 3D warehouse and I’m trying to trim away some unwanted parts and splitting the model in half.
I try to search for tutorial but intersect does not work at all. Here’s the model that I have downloaded. Please help~

Thanks a lot!


A screen shot isn’t much use in this case, please add the warehouse link for the model itself so someone can check it and give you some advice.


Hi Box,
Thanks for reply. Here’s the link of the model.


The skull itself is a component and you need to open the component for editing so you can work on the actual geometry.
Here you can see I double click to edit, fence select right to left half the skull and group it, them move it away.


Hi Box,
Thanks so much for the tutorial, it works!

1 more question. If say I want to split it top and bottom to half, and it will have a lots of rough edges around. How can I trim it to make it clean?


There are several options. But first you may want to soften all those distracting edges. Use the Soften Edges dialog from the Window menu.

Make a rectangle, move it where you want a seam and use it like a cutting plane by selecting the planar face and skull geometry, r-clicking and intersecting.

Try out the plugin Zorro2 (join SketchUcation to download and see the images.) The plugin even has an option to slice along a section plane, which could be used instead of an intersecting face.


You’ve chosen a very complex model to play with so you need to be aware of a couple of things.
When the geometry is as complex as this you need to watch out for the tiny faces problem.
SU has problems forming faces when the edge segments get down around 1mm or the inch equivalent. So when you try to cut something this complex at it’s current size, intersect will often fail to create a continuous edge, making it very difficult to separate the two halves. Also holes will form where edges are too short.
To get around this you need to scale up, edit the large version and scale back down to size.
Or as I have done here, scale up a second instance of the component, edit it and the edits will work on the small version. Once complete you simply delete the large instance leaving you with the original.
So as catamountain mentioned above, I have smoothed the skull with the soften/smooth dialog, then sliced it with a flat face. Make sure the face is within the editing context of the component.


Hey Box & Catamountain,
Thanks so much for the assistance. It works but the edge is not as clean as what Box have shown. Perhaps I need to scale up more.


Yes. Scale up more, the intersection should be clean. For a successful intersection operation, no underlying (hidden) edge should be less than 1/16". The shorted edge may even need to be a bit longer for best result.