Blender Underground

This post was edited to reflect comments below and to add some new items.

Object Origins in Blender refers to the point where an object's center is located. The center may or may not be the true center of that object and can be relocated. Object origins are a big point of confusion with new Blender users and this post will attempt to explain them and offer suggestions in how to exploit them to your benefit as well as some of the downfalls you may encounter when dealing with origins.

First off, what exactly is an object origin? Simply put, it is the point that defines the center of a given object in 3D space. The name is derived from the true meaning of the word reflecting the starting point for an object's location as defined by the 3D cursor when objects are added (more on this later).

There are four main rules for origins.

1. Every object in Blender has an origin.
2. Every origin has an X,Y and Z coordinate and orientation.
3. No single object can have two origins.
4. The 3D cursor defines the origin location for new objects and allows manipulation of the origin after creation.

Why are origins important in Blender? It is the origin that defines where a scale, rotation, movement and deformation occurs. It is the origin that is referenced for path following in animations. It is the origin that is referenced in global and local view orientation. In short, as far as objects go, it is their center of the universe and that universe can be manipulated in Blender!

The following depicts the default cube in object mode:



You should notice 2 things right away. First, the object manipulator is in the center of the cube (AKA the origin) and the 3D cursor is also in the center. For most of this tutorial, I'll be turning off the 3D manipulator for clarity as well as moving the 3D cursor to give you clear view of the true origin point. Just remember that the 3D manipulator will ALWAYS show up on the origin when on (which makes for a handy way to quickly find the origin). The next thing you may notice is that the origin for the default cube is also the global origin of Blender (meaning the X,Y and Z points are all equal to Blender's global "0"). How do you know this? It sits directly on the convergence of the X,Y and Z axis no matter the zoom level (wire-frame view will confirm this). In the following image you will see the origin point itself since I moved the 3D cursor off center and turned off the 3D manipulators:



Now you can clearly see the origin is represented as a pink dot in the center of the cube. As I said before, the origins location can be manipulated. In the next image I have relocated the origin to the 3D cursor:



Because the origin is the center of an object's universe, I have just relocated the cube's universe several Blender units over and down. To illustrate this fact further, I will now center the cube to its new universe:



The controls used to manipulate an origin can be found in the Mesh toolbox located on the F9 tool panel of the buttons window:



The buttons outlined in red and their function are as follows:

Top Left "Center" shifts the objects data to the origin. This will move the object to the origin assuming the origin has moved. If the origin is already in the center, you should see no movement of the object.

Top Right "Center New" shifts the origin to the object's center location. Again, if the origin is already in the center of the object, you should not see any change.

Bottom "Center Cursor" shifts the origin to the location of the 3D cursor.

All of these manipulations of the origin have more purpose than simply moving the object around. As stated earlier, the origin is the pivot point for rotations. It is the beginning point for scaling and the center location for deformations and animations. To illustrate this, let's move the origin way off center then rotate it and see what effect we have:



Move the origin to the 3D cursor (F9-> Mesh-> "Center Cursor").



As you can see, it rotated around the origin. This can be useful for an animation where you have to move an object in a perfect arc for example. Scaling has the same effect by beginning the scale at the origin:



You should notice that as you scaled, the object not only got smaller but moved towards the origin.

A pitfall comes into play when you have multiple objects selected. Blender has the ability to change how the origin interacts with the object by adjusting the "pivot mode" found on the toolbar depicted below:



The buttons and functions are as follows:

"Bounding Box Center" makes the bounding box center the pivot point.

"Median Point" calculates the point in the median of the selected objects and uses that as the pivot point.

"3D Cursor" uses the 3D cursor as the pivot point.

"Individual Centers" uses the origin of each object as the center for rotations and scaling.

"Active Object" uses the last selected object's, AKA the active object's, origin as the pivot point.

The default is "Median Point". This can be seen by turning on the 3D manipulator and noticing the location of it as we select multiple objects:



Any scaling, rotation and deformations will be relative to the average of the objects selected by default. More, they become the combined object's new origin. Lastly, if joined (using CTRL J) this combined origin does NOT become the new origin for the joined object. Instead, the active object's origin (that is the LAST selected object) becomes the new origin:



I hope this tutorial helps clear up some of the mystery surrounding object origins and help provide an effective way to manipulate them for your betterment. It is far better to manipulate the tool than to have the tool manipulate you!

Very well done tutorial. Thanks!

I just hope I don't confuse someone more than they already may be.

I got to studying origins when I flopped the animation for a straight line (and am still flopping on the J2 particles. Don't worry, I'll get it if it kills me... ). Doing a tutorial helps me understand it better because it requires thinking about it first before you can explain it to others. Plus it lets me know pretty quickly if I am misunderstanding something because someone else will catch an omission or error pretty quickly when you post them...

The only thing I noticed is this:


This is really the result of the Median pivot mode. If you choose Individual Centers, for instance, the result is quite different. So it really is a feature, as it's what the Median pivot mode is designed to do.

Still a well done introduction to Origins, and something that's likely to help visitors. Thanks again.

Can that behavior be changed? If so, where?

[EDIT]

Never mind....I found it....On the toolbar...Do'h

Overall, an excellent and well written tutorial. Well done, Penix1.

Very awesome tutorial Penix.

There be many step, step, step-before-step to remember Blender Samba! Ayiii!

Thanks!

I have modified the tutorial to reflect the comments you all have made. We do strive for accuracy here at BU....

You made a nice clean transition into and out of the new material. Well done!

Crap! I just noticed I forgot the whole bit about moving in edit mode doesn't move the origin. That is how this whole thing got messed up for me. "Center new" in object mode of course is the fix but still....

There is a time when it DOES become the new object center. When any doubles are removed, the object origin moves to the new center

I have fixed the images in this tutorial. My bad. I had them on a server that no longer exists. Moving is a pain!

This is nifty, I think that I should reread it every few days. I also like having the properties window open and looking how the data in there changes when fiddling around. Thanks for keeping it updated.

Well, I had two images reversed that I now have fixed. Preview...It makes a body good....