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Knievel
24-Jan-08, 10:45
Question: How do you change the rotation point of an object. What I call rotation point is the point around which an object rotates :)

For example, if it is in the middle of the object, it rotates and stays in place. If you put that point outside the object, when rotating, the object rotates around the point, as if it was facing it and running around it.

So the question is how to find this point for a specific object, and how to relocate it.

Thnx

Knievel
24-Jan-08, 11:04
The problem here is that the object which I am trying to do this with is the camera. I found how to do it with a cube or so. But it doesn't work for the camera. Or does that mean I am doing something wrong?

RickyBlender
24-Jan-08, 13:14
on bottom bar there is sing like Omega uppercase there hyou can choose the rotation point

you can also change the location of the center point of your object point in F9

For your camera i would install an EMpty with a constraint then you can move that empty where you want the camera to look at

Salutations


Salutations

Knievel
24-Jan-08, 17:31
Thanks for the aid, but I'm just getting to know blender and some of your advice sounds like jabber to me.

This is what I'm trying to do.

I have a cube, centered, more or less like the starting cube, but with image textures.
The camera is aimed at this cube (constrained). Now I want to make an animation where the camera rotates around and back (and back and back again) the cube. Allways staying the same distance from the cube.

I tried the center to cursor stuff but that doesn't work with the camera. Also in the "rotate manipulator mode" I cant get this done.

I know how to do the IPO curves stuff, but I cant figure out the rotation stuff.
Is this camera really that different? If so, could I just make the camera child to an empty (parent). Replace the center of the empty to the center of the cube, and then rotate the empty? Would this work? Or would it mess up the constraint camera.

Knievel
24-Jan-08, 18:07
I Tried what I spoke about in my previous answer.

So I made an ampty. Put is at the exact location of the camera. Made the camera child of the empty. And did the "center cursor" thing. The center cursor didn't seem to work for the empty however, so when I rotate the empty, it just rotates with its center still in the camera, and not in the cube (which at location 000).

Why doesn't this work?

IamInnocent
24-Jan-08, 18:12
The page on Pivot points in the Wiki
http://wiki.blender.org/index.php/Manual/Pivot_Points
Now you won't be able to do the trick with the camera, because it has no geometry.
You see Blender describes his Objects with chunks of data called datablocks.
The fundamental datablock of an Object is the... object datablock (tadaaa....). What you called the 'rotation point' litterally is the Object Center. To the Object is linked another datablock that describes its geometry when it has one. That geometry can be anywhere in the space and even completely offset from the Object itself as represented by the Object Center.
Now, if you need to, you can position the Object Center anywhere by positioning the 3D cursor there first then by using the 'Center Cursor' button in the Edit context, Mesh panel.

This helps?

Jean

h2kyeong
24-Jan-08, 20:41
Well, I'm a newbie myself, haven't done any animation yet,
But if you need the camera location / rotation to behave like that of an object,
how about setting an object a parent to the camera?
You can set that by selecting the object to be the parent, then the camera (holding shift, so that both are selected), and press CTR+P then click.
To detach it, select the camera and then at Object > Parent > clear parent
Then when you move that object, the camera follows... To hide this thing, use a 2D object or faceless mesh.
I guess there must be a way without using a dummy parent, but hope this works.

h2kyeong
24-Jan-08, 20:46
Well, I'm a newbie myself, haven't done any animation yet,
But if you need the camera location / rotation to behave like that of an object,
how about setting an object a parent to the camera?
You can set that by selecting the object to be the parent, then the camera (holding shift, so that both are selected), and press CTR+P then click.
To detach it, select the camera and then at Object > Parent > clear parent
Then when you move that object, the camera follows... To hide this thing, use a 2D object or faceless mesh.
I guess there must be a way without using a dummy parent, but hope this works.

Knievel
26-Jan-08, 12:37
Just a quick read and a quick answer.

I tried the thing with the parent. But strangely it didn't work. Or maybe an empty doesn't count as an object. I'll try tomoro and let you know.
While i'm typing this I can't think of any reason why the parent object thing couldn't work. So I suppose an empty doesn't work like an object....

Thanks for all the reply.

Knievel
27-Jan-08, 08:31
For those who share the same problem as I had. Here is how it finally worked out.

Make the camera constraint with the objct you are filming (subject). Then make an object and place it exactly behind the camera. Don't place the object on the camera or you will be filming this object instead of the other one (your subject). Then put the center of the extra object in the center of your subject. Now make the camera parent of the extra object. Et voila! If you rotate the extra object now, it wil turn around your subject, and the camera will turn with it, allways aiming at the subject.

Great!
Thnx for all you help.

Why it didn't work with an "empty"? I don't know.

I was wondering, are there actually lessons I can follow for Blender? Where you get a teacher who know's something about the program?
I'm from Belgium btw.

h2kyeong
27-Jan-08, 09:08
You could try these ones
http://www.gryllus.net/Blender/3D.html
http://homepage.ntlworld.com/r.burke2/tutorial.html

IamInnocent
27-Jan-08, 09:15
Why it didn't work with an "empty"? I don't know.



I don't know either...
Here's an exemple with an empty at the center of the chopper:
http://pages.videotron.com/innocent/helicopter005.blend

You'll noticed that all I needed was an empty 'targetCamera' parented to the 'wholeChopper' empty which is for animating the machine.



I was wondering, are there actually lessons I can follow for Blender? Where you get a teacher who know's something about the program?
I'm from Belgium btw.

Ask around, especially in New and Discussion or on the bf-education mailing list
http://lists.blender.org/mailman/listinfo/bf-education