Vertex at intersection?

tried looking around for it but couldnt find it

just using this picture for an example, but if two lines are on the same “plane” and intersect how could i make a vertex at the intersection point?

EDIT: found a script that will do it, but is there any other way to do it without the script?

Ah, the Compute Edge Intersection script. Well done for finding it, I had to have someone show me…

I don’t think there is, I was surprised because I thought it would come up quite often. Same goes for the bevel-center script I guess.

By the way, what’s with the Satanic imagery? :slight_smile:

Bosh and fiddle-faddle. It’s only Satanic if the point is downward.

Ok. Here it is. No script required.


The pentagram.


Select the edges you want to connect and subdivide multi>>2 cuts


Select the two new vertices on one of the edges, and scale them until one of the vertices is on the intersection. (Zoom in and Shift Scale for extra accuracy)


Do the same with the other edge


Merge. The two edges are now connected with a vertex at the intersection.

The key is to have two vertices on the edge, that way scale will move them both along the edge without disturbing either end point or moving the edge. You’ll wind up with a few extra vertices, but you can delete them and rebuild the edge between the end points and the intersections.

[Oops! Is that pentagram UPSIDE DOWN!!! OMG!!! The devil made me do it :smiley: ]

Subdivide multi it up (same as evil Orinoco)…

Snap the 3D cursor to to top vertex & change the pivot to the 3D cursor. Select the right most vertex and check (and remember) it’s Z-loc in transform properties. Now select the vertex number 1 vertex in the image below and scale till the z-loc matches. Select the number 2 vertex merge (alt+m) it with the number 1 vertext.

Repeat on the left side, then select all vertexs rotate around till the the top vert is where the right most vertext is and off you go again.

Hope that made sence, you should end up with perfect intersection points. :wink:

Attachments


Not bad. Not bad at all. But this part

only works because the first intersection is on a (presumably) horizontal line. After you rotate the object, what’s to guarantee the new horizontal will actually be horizontal? I suppose you could go back to the transform properties dialog, check the end points, rotate the object a bit closer, check again, rotate again… whew.

A better way to use transform properties to get an absolutely accurate intersection vertex would be to slide the first vertex to the approximate correct location then check its x,z coordinates, then slide the second vertex to the same location (or as close as you can get it), then go back and adjust the first vertex to match the second vertex.

This handles the general case and doesn’t rely on any edge in the object being absolutely horizontal (or vertical) for it to work.

I didn’t actually try (as you prob guessed but the pic), I figgered with the pentagram shape it would be a whole degree rotation that could be easily snapped to. If that’s not the case or you had a different shape, checking and rotating should be easy (rotate close, check horizontal/vertical position and then one fine rotate should be all). Bit quicker than zooming right in and sliding the verts till they match (well is for me).

Sure would be nice when blender has propper snapping tools… :smiley:

This problem is just begging for a Python script.

N30N: You say tomayto, I say tomahto… I think it’s mostly a workflow thing. I usually work full screen close up anyway, so the zoom in thing is not an issue. You’re right about snapping tools.

Hey, Zach! it’s your thread! Any of this stuff of use to you?

sorry for not replying i dont have a home computer at the moment only at work where i am at mon-fri

but ahh yes very useful thanks a lot everyone for the help :smiley:

Switch to edge mode, select the two edges that cross, zoom in as close as possible to the intesection, use the knife tool (cut exact) to cut the edges at the intersection, switch to vertex mode, select the two new vertices, press w, choose merge (at center), done.

http://www.fourmadmen.com/blender/scripts/4mm_edge_intersection.html

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