as a user of blender for architecture it has come to my attention that there’s something missing from blender that would be amazingly helpful for anyone using it for architecture or even to visualise any sort of component for product design etc.
I know its possibly a big ask but is there any way to make blender convert a plane into section plane?
this is the way a section plane works in sketchup. basically it takes the plane, makes it invisible for anything facing in the other direction of the normal. in addition to this, as you can see in the picture, the lines where the plane intersects are thicker and can, in orthographic view, be exported as scaleable lines.
so, is it possible for anyone to code this sort of thing as an addon?
again, i know this is a huge ask but this would be an incredibly useful program for anyone using blender for architecture.
the thing is, its quite difficult to set the node method out and in addition to this it would be immensely helpful to be able to export the line of the section cut as an autocad file. in addition to this being able to turn this plane into some sort of section cut tool that could be turned off or on you could quickly and easily obtain section cuts of your model. being able to do this would mean that you could combine the beauty of blenders rendering and modeling capabilities with other more precise programmes to draw in additional details.
atom! thanks for getting back to me. ive already done the start clip thing. but what im looking to do is something more like this:
/uploads/default/original/3X/8/e/8eff5ec37a8d779de2fc9b2f384a9f748ed07dc4.jpg
i know it can be done but cant figure out how exactly.
I don’t think that this is asking too much. A quick sectional view which could be moved with a mouse would be an invaluable help. I use Blender for various visualisations including looking at mechanisms to get a better understanding of the way things work.
Bump. Any news on this front? It’s been half a decade and a couple handfuls of Blender versions. Unfortunately I wouldn’t know where to start coding something like this myself, but it would be a really useful addition.
@scyg perhaps alt-b is what you’re looking for in the 3D viewport? It will cut a section. Not as friendly as the “section box” in SketchUp, but does the job.
No, that’s unfortunately not it, either. While it could be used to preview, it doesn’t render, not to mention getting anything approaching a drawing out of it. Thanks for the suggestion though.
Here’s a purely shader-based slice that works with a plane. It only works properly in Cycles, though if there’s no occlusion happening (like the grey cube in my example needing to be untouched) I think it could work in EEVEE as well (minus the capping). For larger scenes it’s a bit tedious to set up, because this needs to be added to each material that needs to get sliced. The slice plane itself has a material as well, so that the sliced geometry gets capped, instead of showing its backfaces.
The general workings are rather straightforward, with the Texture Coordinate node checking if pixels are above or below the plane object (taking its rotations into account), and using this to drive a Mix Shader node to render as either a fully shaded material or a Transparent BSDF.
The material of the slice plane is a bit more finicky, since it relies on the Ambient Occlusion node to decide, whether a pixel lies inside or outside of the sliced geometry. Even with a ColorRamp set to Constant, getting a sharp edge on AO is still difficult, but increasing the samples count in the AO node(s) sometimes helps. What doesn’t work with this concept is, obviously, the bevel node, as the newly created edge between the sliced object and its cap is purely visual trickery between two (or more) unconnected objects, and not an actual geometry edge.
The slice plane can be turned off for rendering, or you set its material to Transparent and not cast shadows. Either way, I don’t see a way to cap the slice (since the AO node isn’t doing much good working only in screenspace AND forcing the same settings as the AO used in the actual rendering). Also the inside of the sliced geometry is still receiving shadows, as if the geometry isn’t cut open, so the only thing to do is tint and/or light up that inside with the Backfacing value of the Geometry node.
@ninehunred I have posted a feature request on Right-Click-Select - I assume this would be very useful to you (to me too, and many other architectural users!), so please feel free to visit and add your vote to increase its exposure to the Blender devs:
In the meantime, the shader solutions are a nice workaround, especially the Eevee one.
