# Why does the behavior of snap seem “weird”?

So, to test volume in luxrender, I am setting up a series of diffraction: I want some water in a glass beaker, or something like that. Problem: the fluid simulator is incredibly slow (granted, my meshes are kinda high resolution) so I decided to simply go Ah! I'll just snap some items together - for example, I'll just take a cylinder and snap it to the edges of the beaker on a transform!

Well, whenever I try to use snap, it looks like this:

Not, that is not a short beaker; that is my beaker snapped to the plane everything is sitting on right in the middle of the beaker. I can guess why you might want this behavior, but I can't get the snap tool to do anything useful!

So my question is: how can I get the bottom of the beaker to snap to the plane, the bottom of the cylinder to snap to the bottom of the beaker, and the sides of the cylinder to snap to the sides of the beaker!

Thanks, this has been incredibly aggravating. (I normally include a link to a blend file, but this is a two minute setup.)

• I believe face snap snaps the pivot point of the object to the face. Try setting the pivot point to the bottom of the beakers. – PGmath Dec 19 '15 at 13:12
• It could be faster to select and duplicate inner geometry of the beaker than trying to snap another object to the beaker's inside. You should keep in mind that the cylinder representing the water must have the same size as the beaker so it may be hard to achieve with another object. Although this may be achieved with using several types of snapping at once. – Mr Zak Dec 19 '15 at 13:41

I believe you need to use the 3D Cursor for this.

In few words, you need to position the origin of the object in the right place first, then position the 3D Cursor where you need the object "by it's origin" to snap to.

1. Select the breaker.
2. In Edit mode select the bottom faces of the breaker, or a central vertex/edges/faces.
3. Shift + S > Cursor to Selected, now you have the 3D cursor at the bottom of the breaker in the center.
4. Go to Object mode.
5. Ctrl+Shift+Alt+C > Origin to 3D Cursor, now you have the origin of the breaker in the bottom center.
6. Select the plane, in Object mode, Shift+S > Cursor to Selected, again this will position the 3D cursor in the center of the plane.
7. Select the breaker, Shift+S > Selection to Cursor, now you moved the object "breaker" with the new origin that you positioned in step "5" to the center of the plane.

Hope this helps.

• Thanks for editing Mr Zak, looks much neater, I'll learn how to do this stuff for next answers! – Georges Dec 20 '15 at 22:47

Snapping in blender is a little weird. It requires some learning and even then some times does it's own thing.

However in this video you can see how to go about it.

You select vertex snapping and then Grab the cube when your mouse is over a vertex. Then you move the mouse over the vertex you want to snap it to.

Not visible due to limitations of screencast keys but in the video I press Z (see status bar) in order to just bring the cube on the plane. Same goes for X Y. Shift+Z constrains movement in the Z axis and allows the other two.

Using this technique you can snap almost everything to everything, and in any combination of axes.

For example in this video you can see how to snap the cube to the intersection of the two planes.

You can also see the weirdness I was talking about before. Despite the fact that my cursor was over the left corner on the cube when I pressed G the cube refuses to snap to the left side and snaps to the right. Usually a reposition of the view or a back-and-forth movement of the cube solves this and you are able to snap everywhere again. I guess it has something to do with the depth perception blender has of the mouse cursor.

PS. Sorry for not posting gif's but I don't have a gif screencaster right now. This SE should allow inline ogv's just because it's so easy to make them with blender.