Essential Blender -Mirrorring problem

Support Modeling
#1

Hi,

I am using blender 2.49a (Suse Linux 11.2) and I am working through the mesh modeling part of essential blender. I am on page 84 now where I am creating a mirror of a plane, but whatever I do, I don’t see the mirror appearing.

What could be wrong?

Cheers
Erik

#2

Blender mirrors along the axis of the object center (the large dot). When you moved the plane did you do this in edit mode or object mode. The book said to move them in edit mode. When in edit mode the center does not mode, in object mode the center moves along with the vertices. If you move in object mode, your mirrored object is on top of your original so you can’t see it.

#3

Solved it myself. The tutorial is a bit strange in that it is suggesting that the mirroring takes place around the x and z axes whereas it takes place around the center of the object.

An explanation is on http://wiki.blender.org/index.php/Doc:Manual/Modifiers/Mesh/Mirror

Cheers
Erik

#4

This is really subtle. So the example depends on the center of the object remaining at the origin when the object is moved in edit mode. I think some more explanation about this would be helpful.

#5

Add a plane, in object mode move it. You can see the center (large pink dot) moves with the plane.
In edit mode select all vertices (A), move them. You can see the vertices move but the object center remains where it is. If the center is in the middel of your plane and you mirror it, all you are doing is mirroring it on top of itself. In your original problem, go into edit mode and move the vertices, you should see the effect of the mirror modifier show up as you move them.
To mirror, you need to mirror about a particular point, this is the object center and can be anywhere, not just at the grid centre.
Mirror modifier http://wiki.blender.org/index.php/Doc:Manual/Modifiers/Mesh/Mirror
Objects http://wiki.blender.org/index.php/Doc:Manual/Modeling/Objects
Meshes http://wiki.blender.org/index.php/Doc:Manual/Modeling/Meshes

#6

Thanks, I fully get it now. At least the educational effect is quite big after spending a couple of hours on it.