Aligning objects

[Mik]

I am having trouble with something that ought to be simple.

I create a cube and a cylinder and combine the two into one via Add Solids.

I want the sides of the cylinder to align with the sides of the cube. (They are both the same dimension in that direction.)

I have snap-to-objects and snap-to-intersections on. I align them, perform the add, and the resulting combination is not aligned. I can still see the edges of the cylinder protruding from the cube (where I don't want to see it any more).

If you snap the objects together on a plane and then zoom way down to them I find they are not aligned. So I try to line them up manually at a hyper zoom level. Perform the Add Solids again and they still won't align.

Why isn't the snapping doing its job? Is there an additional setting I need to check for that?

I turned off snapping to the grid some time ago and these objects are in a blank field so there is nothing else to interfere with the snapping (or lack thereof).

Trying to detail some corbels and frustratingly stuck!

Anyone else experience this?

[Benson Shaw]

Assuming the desired solid addition is a cube with a cylinder growing out of one face, such that the axis of the cylinder is normal to the plane of the cube face and the axis passes through the center of the cube face. Sort of a round peg with a square head.

Misalignment could be one or more of these:

?Are these extrudes? 2d/3d conversion settings or render settings (esp OGL) might might be too low. Display of cylinder would be faceted, and therefore not match the expected diameter, esp when rendered.

?Cylinder diameter value does not equal the cube edge value.

?Cylinder axis is not normal to cube face.

?Cylinder axis does not pass through center point of cube face (misaligned).

Maybe a redraw would help. in Top Plan view

Draw a square with the rectangle tool.

Draw a circle centered at center of the square. Diameter = length of square edge.

Extrude the square to make the cube.

Extrude the circle to make the cylinder.

In the circle OIP, adjust bottom z value to equal height of cube.

Add solids if necessary.

This produces the desired alignment.

Good luck!

-B

[Mik]

Actually, the cylinder is offset from the cube so I could see its round side protruding from the cube once the solids are added.

A couple things I noticed after I read your post:

- I created a new cube and cylinder in top/plan view and it added the solids fine.

- In my project situation, I had created the cylinder in the right view. I noticed that it doesn't like to snap very accurately from that view.

- Also, the "cube" I want to use is actually a solid subtraction where I removed a couple chunks. I wonder if VW behaves differently with that. When you mentioned the bottom Z height I checked the OIP for both and the solid subtraction does not have that field.

- I created a new cube, took a quarter out of it with a solid subtraction, and then tried to add a solid cylinder with the same length. Moved it into position via the snapping and then added the solids. I can still see the edge of the cylinder protruding for what appears to be millionths of an inch but enough to show.

Is the problem here that VW does not handle the solid subtraction as accurately as a simple one-step extrusion? And/or that I am attempting to align the objects in right/back/etc. views instead of plan view?

[mac@stairworks]

What about using align/distribute and align the objects to their centers

[Benson Shaw]

That z height field is in the extrude PIOs. Edit (dbl click) the solid to get to the nested objects.

What about using align/distribute and align the objects to their centers

This is a great process as long as the objects are in the correct planes/attitudes, and, in this case, the symmetry of all objects is consistent so that the centers of the extents are at the desired points. If there is a chunk out of the cube, it could displace the center.

-B

Edited June 23, 2014 by Benson Shaw

[Mik]

The centers of the cube (in one plane) and the cylinder are intentionally off center. The part that is not aligning is in the "extruded plane".

Anyway, I don't know why it won't work when doing it from any other view other than top/plan but once I recreated the object from that view it lined up fine. After I create it there then I rotate it into the proper position.

Back to work!

(And thanks for taking the time to reply here. Just hearing from the experts gives me info I had not considered.)