Scaling dome to match diameter of circular mesh


I started learning Blender yesterday, so please excuse my current state of less-than-blissful ignorance. I should note that I’m using version 2.57.

I’m trying to scale a dome (which was created by making a UV sphere and removing all the vertices below a horizontal line) so that it fits “properly” on top of a cylinder (i.e., without any gaps and scaled properly). Both the perimeter of the cylinder face and the bottom of the dome are circular and made up of an equal number of vertices but are of different diameters. I’ve been able to centre the dome on the face of the cylinder and make it flush using the snapping tools, but I can’t seem to scale it such that it fits on the end of the cylinder (i.e., such that the vertices of the face of the cylinder and the bottom circle of the dome are coincident).

I’ve tried using the scale tool with snap to closest vertex turned on, but this doesn’t accomplish the desired result: the dome is scaled, but the diameter of its bottom circle is still less than that of the cylinder face. I think I need some combination of a scale operation and a translation along the Z axis, but simply doing one after the other doesn’t work since the dome isn’t scaled to the desired size.

Any assistance would be appreciated - I’ve attached an image demonstrating the current state of my model (see below) and also my .blend file.


dome_test.blend (393 KB)

i havent downloaded the blend but it appears that there is a vertex on the cylinder located at the center of your hemisphere; select that vertex, ctrl+s->to selected. then change your pivot point to “3D cursor” and scale.

or instead of selecting the vertex, you can loop select the bottom edge loop of your hemisphere, ctrl+s…

or you can select your hemisphere, then select that vertex, change your pivot point to “active element” and then scale.

in order to join the two objects, first i recommend you delete that vertex, select all, then “remove doubles.” play around with the tolerance to get it to work right. you really dont need to be all that precise when working in 3D.

You should be able to use vertex snapping to scale the dome to fit the cylinder

Thanks max11D, changing the pivot point to the vertex at the centre of the cylinder face via the 3D cursor worked perfectly.

Hmmm? Why go to all of that trouble? Why not just take your sphere, cut it in half, scale it to your pleasure. then extrude the bottom vertices to form the cylinder?

that works too, but my convoluted ways are more informative. now he has befriended the 3D cursor :stuck_out_tongue:

still, it is a valid point…always look for a simpler way to do something.

i was thinking something along ctrlaltdel’s solution heh
i wish you luck in your blending endeavors, reign

Of course, if you actually need those inside faces on the top of the cylinder (as in having a hemisphere docking or leaving the cylinder in an animation) there is really no need for them. In that case it would be two separate objects anyway and your hemisphere might need to be closed on the bottom as well. Just food for thought…

Happy blending!