What tool or SOP should I be using to create non-procedural points interactively in the viewport? These points will be used for instancing and aren't part of any primitives - just points in specific places lying on existing geometry. I'll be using various snapping features to place the points. Thanks.

You could try the skeleton SOP. Only annoyance is that you have to press MMB after each point to not create a chain.

Cheers
CYTE

Hello. First thought that comes to mind is Add SOP where you're just going to add points and manually transform them with snapping enabled from {0,0,0} position to desired spot on the mesh. It wouldn't generate any primitives.

If you want a more interactive experience where you can simply click in the viewport on the mesh itself to generate points, you could use Curve SOP with Primitive Type set to "Polygon". Add as many points as you want on the mesh, ignore the curve that's going to be generated. Afterwards, simply place Add SOP and check "Delete Geometry But Keep the Points" toggle. That's going to remove the primitives.

Another alternative is Stroke SOP. It's got projection functionality built in. Just plug in your mesh in first input (Projection Geometry) and change Projection to "Geometry". Then press enter in the viewport and place your points. Disadvantage of this node is that it's going to create almost 20 unnecessary attributes. So you should drop Attribute Delete to clean them up, followed with Add SOP (Delete Geometry But Keep the Points).

Each method has its pros and cons so see what suits you the best.
I hope this helps!

Topobuild.

Click once to lay a point, MMB once to cancel the quad creation, then you can continue left clicking as much as you want to lay more disconnected points. You can easily reposition points after laying them and you get the benefit of the brush tool to smoosh them around if needed.

Thanks, all. Think I'll build a custom HDA based on the Stroke SOP to do just what I want. Doesn't look too difficult. There's gonna be other artists using it, so worth the effort. Kinda surprised there's not already a built-in SOP to do it. Anyhow, it might end up on Orbolt if it proves useful enough in our pipeline.