Matching angles in blender

[Deleted User]

I'm the user known as judge death, I lost my ISP and email with my pass and couldn't remember it, so I logged in as judge death!, so if you sent me a PM and I didn;t get it you know how to get it to me now.

ANyway, I'm having an issue with blender and angles. Say I create an object with an angled surface aND i WANT TO match another object to that surface flush on.

For an example we can all understand, sayI create an imperial star destroyer, we all know what those look like, right? Now the basic hull is fairly simply in any 3D program, yes? Now suppose I want to make some bits to put on the hull, and I need to get them to match the angles of the flat plane of the main hull exactly so they stick to it flush? Short of the slow, laborious and ineffective practice of eyeballing it and getting a half assed result that will always be at least a fraction of a degree off, is there any way I can get blender to calculate the angle of a surface relative to blender's reference frame and tell me the angles so I can rotate another object to the exact same angles so the two object are flush together?

Melak

If you contact a mod or admin, I'm sure they can sort your account trouble with you

As for your question - I don't use blender but 3ds max has a couple "align" tools, one of them "align to normal", see if blender has anything like that.
Also, a different option would be to cut the bits you want to place on the surface out of a copy of that surface, then all you need to do is cut it to the proper shape and extrude.

tetsujin

Judge Death! wrote: »

For an example we can all understand, say I create an imperial star destroyer, we all know what those look like, right? Now the basic hull is fairly simply in any 3D program, yes? Now suppose I want to make some bits to put on the hull, and I need to get them to match the angles of the flat plane of the main hull exactly so they stick to it flush? Short of the slow, laborious and ineffective practice of eyeballing it and getting a half assed result that will always be at least a fraction of a degree off, is there any way I can get blender to calculate the angle of a surface relative to blender's reference frame and tell me the angles so I can rotate another object to the exact same angles so the two object are flush together?

The main method I know of for doing this goes something like this:

• Select the face you want to align to
• Align view to selected (top) (Shift-V 1)
• Create an object

That new object will be created with its orientation determined by the current view, and its position determined by the 3-D cursor position. If you already had an existing object that you wanted rotated to this same orientation, you could select that object, and then shift-select the object whose orientation you want to copy, and copy rotations (ctrl-c 2)

Or, if you wanted to add stuff to the existing object instead of adding a whole new object, you could do that, too, by adding a mesh in edit mode after changing view, instead of adding an object in object mode...

If all you want to add is another plane, in some cases it's easier to just extrude it. Even if you're not extruding perpendicular to the surface (for instance, the buildings on top of the star destroyer's hull are extruded "up") you can do that by setting a constraint on your extrude operation (extrude-z, (e z))... But to extrude just the area with the building on it, and not the whole top deck, you'd need to split the top deck faces to get the shape you need... Again, align to view/top (Shift-V 1) is very useful here. Adding vertices is simple enough without affecting the surface (edge split, cut tool, whatever) but moving them around can be a bit of a problem (there's things like edge slide, but for that you need edges selected - not just a vertex)... So if you align your view to the surface a vertex is on, you can move that vertex around without disturbing the orientation of that face.

And finally - I'm no expert modeler but it seems to me that sometimes it's just not that important to get an orientation perfect. "as good as I can get it after zooming in" is often quite good enough... But my desire for perfection led me to learn the things I mentioned above. Good luck!

[Deleted User]

If I create an engine as a separate object can I align it to the hull by using the above? I was able, eventually, to get the hull section in question alighed to the view by using the * key after I selected the plane and made a face of it, but I still cannot tell what angle the view is at to make it flat. If I could get that I could just make the damned engine and then rotate it to the right angle...

[Deleted User]

ll blender really needs is a simple protractor function that lets people determine the angle of a surface so they ca rotate an object to be aligned to it to the same angle, and I;'m tired of beating my head on inadequate solutions that don;t work. Untuil blender gets a protractor fuction I have to say I can;t use it.

tetsujin

Judge Death! wrote: »

If I create an engine as a separate object can I align it to the hull by using the above? I was able, eventually, to get the hull section in question alighed to the view by using the * key after I selected the plane and made a face of it, but I still cannot tell what angle the view is at to make it flat. If I could get that I could just make the damned engine and then rotate it to the right angle...

Yeah, I described how to do this... Select the face you want to align to, align the view to the face, create an object in that view. If you like to edit your engine object un-rotated, you could then change the mesh for that new object, link it to use the same mesh as your engine object. (Click the pop-up button where it says "ME:Cube" and select your engine object's mesh from the pop-up list...)

Of course, if you're not going to use Blender any more then I guess you don't need this information.

[Deleted User]

Professor Null showed me the solution: In the mesh tools more panel in edit mode, down in the lower part of the screen, there's a couple functions to show edge length and show angle. Turn them on, select a face and you can get the EXACT angle to 3 decimals. I made the engine, rotated it to the value I got and Viola!

No docs for blender had ever explained that function to me, which was a shame.

Here's a link to the page where profnull showed me the way: http://blenderunderground.com/forums/viewtopic.php?f=2&t=4660&start=15
It can be a little tricky to use, as it only gives angles on corners, but I found out how to make it work. Sometimes you may need to create a new face with plat plane attached to the angle you wish to measure to get the angle, and sometimes on things that angle along 2 axises you may need to do it twice, but it does work, and with results accurate to 3 decimals it works extremely well.