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Old 28th December 2005, 07:50 AM   #1
Hawk
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Default Joining objects

What is the better way to join two objects as one without a visible joint line showing in the final view? Say two identical square boxes into one object without any joint lines.
Also when mirroring I get a series of dots at the joint line?
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Old 28th December 2005, 08:38 AM   #2
luuckyy
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When mirroring an object to make a single one, you have to take care that the vertices that will join (themselves) with the new ones, are aligned (to the Y axis for example) ... Maybe you already did that, I don't know ?

OL.
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Old 28th December 2005, 10:50 AM   #3
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I'm not sure what you mean, but it seems no matter what I do if I rotate the object a certain way I do see smallish dots or a faint broken line.
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Old 28th December 2005, 10:54 AM   #4
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Also the object are sometimes aligned using the snap to grid function so they should be in the exact same place, yet I do see a faint line. Like two identical boxes brought together on one grid line. Try it.
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Old 28th December 2005, 12:45 PM   #5
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Hi Hawk,

For joining two pre-existing objects:

Try a "Vertex -> Snap Together by Distance" command with the vertices to be joined selected. I use a tolerance of 0.0005, which is probably fine for most cases, but it depends on the size of your geometry what tolerance you wish to use. Once this is done, "Object -> Merge" them and perform an "Object -> Optimize Vertices". This should get rid of your seams.

For mirroring:

As luuckyy suggested, when mirroring, make sure the vertices at the "seam" where the mirror will occur are exactly lined up. It's best to move your object so these vertices are exactly on the axis where the mirror will take place. For example, if mirroring along the X axis, position your model so that the "seam" vertices are exactly on the X axis before hitting the switch. To be doubly sure that they are on the axis, use the "Vertex -> Align to Axis" command on these vertices prior to mirroring.


When you are using "snap to grid" you would normally expect that all vertices were in the exact same spot, but, unfortunately, this still isn't necessarily so.

The reason behind this is often due to the way computers perform floating point arithmetic. It's a fairly involved explanation, but suffice to say, you may have two points that you think are at 0.0 on a given axis, but one of them may be off by a *very* small amount.

There's actually a Microsoft knowledge base article that gives a light explanation of this issue at http://support.microsoft.com/default...b;en-us;214118. The article applies to Microsoft products, but the principle applies here as well.

Good luck,
Dennis
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Old 29th December 2005, 08:39 AM   #6
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Thanks Dennis, I have printed your instructions and will see how it works.
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Old 29th December 2005, 01:59 PM   #7
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Please tell me what happens when you mirror a box, do you see a faint line? I do Thanks
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Old 29th December 2005, 04:17 PM   #8
luuckyy
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1) Creating the box


2) Selecting the 4 vertices from its side


3) Aligning the vertices to the X axis


4) Mirroring the object on the X axis


5) 3D view of the new extended box
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Old 29th December 2005, 04:44 PM   #9
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http://www.tomah.com/DElliott/box.gif
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Old 29th December 2005, 05:12 PM   #10
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Hawk,

I get the same results as luuckyy if I turn on "clean" view, and I get the same results as you if I leave it on normal view.

What you're seeing is 2 surfaces in the center of the mirrored box.

To get rid of these, you have 2 options --- the easiest is to remove the surface on the right side of the box (the side where you're mirroring) before you actually perform the mirror.

The second option, if you already have the box created, is to follow luuckyy's creation steps, but at the end, do this:

1. Select the entire mirrored box.
2. Enter Surface mode
3. In the Front view, Shift + right-drag over the surfaces on the left and then to the right of the center line. You should be left with only the center line/surfaces selected. You can now delete these.

Let us know if that makes sense.

Either of these approaches should get rid of the line you're seeing.

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