I want to be able to use vector hatching both manually and as section fill. Many plan / elevation / section views are done in hidden line rather then full color, and raster patterns are not effective in these views.
Just another feature that better CAD software has that Sketchup painfully lacks.
Kinda like CIRCLES.
The idea of SU is a simple core around witch you can add extensions. Some extensions should/could joint the core tools, I agree, but many more are niche.
Pretty sure the idea here was that hatching section was a presentation tool, therefore in layout, and not a modelling tool in SU. I don’t even recall if LO has vector hatches or still the raster ones.
Since this is the was SU is built, you may consider extensions like Curic Section or its lite version. They allow you to use hatches when making sections in SU, no idea if they are vector though.
in term of geometry, it’s easy to make a 2d circle in a CAD program.
Making it 3d, cylinder or sphere poses a problem. it’s more complex and ressource heavy due to a guy named π.
Some 3D softwares will work with volumes and nurbs. they make vector volumes that are mathematically exact but more difficult to work with.
some other will work with polygons and faces. SU is one of those. they are less precise but allow for more flexibility and freedom.
Nurbs are great for making exact volumes, but polygons (triangles and quads) seems way better for… computational power, rendering, ray tracing… pretty much everything else.
And funny enough, it seems that even Autocad, the CAD reference, lies about the circles. You can choose how smooth they appear, just like in SU. I guess it’s a vertex/face based software too (feels kinda logical)
When working CAD, the thing that actually matters is the ability to adjust the resolution to a point you won’t see the polygon (more segments for eg.) and the ability of the software to remember in the metadata that it’s a circle, so when it comes to measurement and volumes, it uses the proper equations.
Decades in Autocad here. Circles in autocad are real geometric circles, you just choose how jaggy they render on screen for speed. But it will do the math correctly to find intersections and tangents etc. Sketchup does not do that with precision, which sometimes impacts my work. I understand the sacrifice for speed but it really hurts and frustrates sometimes.
I would be fine with a plugin for the hatching - but there isn’t one that does it how I want. Maybe someone will write one, but I don’t reckon I should hold my breath.
Layout should have plugins to customize it, and doesnt, and continues to be SLOW to contrast the relative speed of Sketchup’s main program.
preach !
this IMO is what makes LO so weak in this tandem, you get SU, start vanilla, add extensions, develop your own personalised tool, then you land in LO, start vanilla, and hit a wall, sorry, nothing else to see, yes the software is a bit rough around the edges and lacks many things, and that’s it.
I think the reason we don’t have a vector hatching system in SU is similar to the circle issue, textures, materials, hatches are raster because of computational power, if they were vector, you could zoom in infinitely on them, and it would cause issues with them. I’m probably both not too far off, and completely off in my reasoning though 
well SU kinda does.
ACAD works in a file basis, everything is detailed at once. SU lets the user choose shape by shape.
However, when math is needed, they will both use the metadata that says “this is a circle” and use the proper formulas.
Regardless of the amount of segments, the same circle will have the same area and perimeter.
Main difference I’d say comes from the way lines behave. In autocad, if 2 lines cross, you still have 2 lines, in SU they cut into 4 lines. Meaning that in SU, your circle can quickly stop being a circle, hence loosing its attributes.