From BlenderWiki

Adding an Object

This is a menu you are going to use a lot! It allows you to add something to your current scene, being a new mesh, a new camera, a new armature…

Options

Here we will just shortly describe the first-level menu items. The sub-menus, when present, show you a choice of “primitives” of the same type, described in there own parts in this manual (follow the links!).

• Mesh – The main type of object in Blender, defined by set of points, called “vertices”.
• Curve – Another important object type, that defines parametric or vectorial lines or flat surfaces, using control points.
• Surface – The “one-more-dimension” version of Curve, defining smoothed curved surfaces.
• Meta – This is a procedural (mathematical) type of object, defining closed surfaces (volumes) blending into each other smoothly.
• Text – Another type of “curves” are pieces of text (fonts are vectorial, after all!).
• Empty – As you might have guessed, these objects contain no data at all (there are mainly used as invisible markers/reference points)!
• Groups – This adds a sort of “proxy” object representing the content of a given group…
• Camera – Adds a new camera (the eyes of Blender…).
• Lamp – Adds a new lamp (the lights of Blender…).
• Armature – Adds a new armature (skeleton).
• Lattice – Adds a new deformation cage.

A new object is always added at the current position of the 3D cursor. But it might be added directly aligned with the current view orientation (i.e. rotated regarding the global coordinates), if the Aligned to View button is enabled, in the Add new objects group of the Edit Methods “tab”, User Preferences window. Else, it has no rotation (i.e. is always aligned with the top view, 7 NumPad).

Note that when adding some objects, they might prompt you for some additional parameters (like the number of vertices, …). After adding some object types (like meshes or curves), you may be immediately placed in Edit mode – this depends whether the Switch to Edit Mode button is toggled, in the User Preferences window, Edit Methods “tab”, Add new objects: group. Edit mode only works on one object at a time, the active object.

Deleting an Object

Erases or deletes selected objects.

Joining Objects

Joins all selected objects to one single object (the objects must be of the same type). The center point of the resulting object is obtained from the previously active object. Performing a join is equivalent to adding new objects while in Edit mode.

Global Undo & Redo

Blender has an optional global undo&redo system, as described here, which allows you to cancel nearly every operation you just have done…

Basic Editings (translation, rotation, scale)

Once you have a selection of one or more objects, you can grab/move (G), rotate (R) or scale (S) them, like many other things in Blender, as described in the Manipulation in 3D Space section.

However, there is one more option to set the location/rotation/scale of an object: you can copy & paste these properties between objects, as described below.

Copying Attributes Between Objects

Description

Blender has a general purpose way of copying any active object’s attributes to any number of other selected objects. For example, if you copy one object’s location attribute to another object, that second object will be “moved”.

Options

The attributes that can be copied include:

• Location.
• Rotation.
• Size.
• Drawtype – Wireframe, shaded, … All settings except Layers and Object Color, in the Draw panel (Object context and sub-context).
• Time Offset – The TimeOffset option, in the Anim settings panel (Object context and sub-context).
• Dupli – The various duplication options, here again in the Anim settings panel.
• Object Color — Back to the Draw panel…
• Mass – The Game Engine Mass setting of the physical engine.
• Damping – The Game Engine Damp setting of the physical engine.
• All Physical Attributes – All the Game Engine physical engine settings.
• Properties – The Game Engine “variables” system. You have the options to Merge All properties, to Replace All properties, to select a specific property to copy, or, if active object has none, to Clear All properties from other selected objects.
• Logic Bricks – The Game Engine control system.
• Protected Transform – Copy the “protected” state of transform properties, not the properties themselves.
• Object Constraints – See Constraints.
• NLA Strips – See Non Linear Animation.
• Texture Space – I.e. UV mappings?
• Subsurf Settings – A specialized modifier copy…
• AutoSmooth – The Auto Smooth settings (meshes only!).
• Object Pass Index – The PassIndex option, in the Object and Links panel (Object context and sub-context). See this page.
• Modifiers... – You have the option to copy only one type of modifiers, or all assigned to the active object. See Modifiers.

So, if you ⇧ ShiftRMB -select a cube and a cone, and then ⇧ ShiftRMB -select a lamp last (the lamp thus being the active object), and choose CtrlC 1 NumPad, the cube and the cone will be “moved” to the same location as the lamp!

Converting an Object

The only way to change the type of an object is to convert it with AltC. This is only possible in a few cases (mainly from curves/surfaces/texts/metas to meshes).

Note that it is a destructive operation, meaning that you generally can’t reverse it (of course, you still have the global undo/redo options).

Centering an Object

These three options allows you to automatically modify the relative position of object data (i.e. vertices or control points) to the object’s center. A bit like, in Edit mode, selecting all elements and translating them.

ObData to Center

Also available through the Center button of the Mesh or Curve and Surface panels (Editing context), this is the only option working also in Edit mode (but with some specificities, see e.g. this page for meshes). It moves the object data (in a block) so that the object’s center and the object data barycenter (median point) are at the same position. Note that even if the shape of the object moves, technically the object itself is not translated because the reference point (the 'center') does not move.

Center New

Also available through the Center New button of the same panels, it moves the object center so that it is at the same position as the object data barycenter (median point). Note the difference with the previous option: here, the object’s shape does not move, only its center point. So, technically, the position of the object is changed.

Center Cursor

Also available through the Center Cursor button of the same panels, it moves the object center to the 3D cursor location. As with Center New, the object’s shape does not seem to move.

Aligning an Object

Description

Align (the local axis of the) selected objects to a specific Transform Orientation.

Mirroring objects

Mirroring objects is basically a different application of the scale tool – it is effectively nothing but scaling with a negative factor in one direction. For example, to mirror in the direction of any single axis:

Mirrored Frustum.

• Enter Scale mode.
• Select an axis using X, Y or Z key.
• Enter “-1” as the scaling factor.

(Mirrored Frustum) is an example of mirroring a frustum object along the Z axis. These are the steps to mirror the frustum:

• Enter Scale mode.
• Select the Z axis using the Z key.
• Enter “-1” as the scaling factor.
• Hit ↵ Enter.

However, for convenience, mirroring is also available as a specific tool. In Object mode, it should be limited to the Local transform orientation (Object space), even though it is possible to choose the World one when using CtrlM. Any other orientation might give strange results. The following example shows what could go wrong and what a proper result should look like.

Only Local space works for mirroring in Object mode.

On (Only Local space works…), the red teapot is a mirrored copy of the blue one along the Global Y axis. Because the blue teapot is rotated relatively to the World this mirror resulted into an upside down copy of the original. Any transformation that is made at an angle from the Local axes of the transformed object will give wrong results. The green teapot is also a copy of the blue one but is has been mirrored along the Local Z axis of that same blue teapot, resulting in a perfect mirror copy (colors were added afterwards).

Mirror menu in Object mode.

On (Mirror menu in Object mode) we can see the choice of the three Local axes which are the only ones usable. Notice also the shortcuts to the extreme right : they are (quite) wrong, as you have to type the axis key twice to use the local space (with only one hit, you will be in world space!).

When you use the CtrlM command, you enter interactive mirror mode, where you can choose the mirror axis using the same actions as with axis locking. If you hit an axis key just once, you will use the global axis. If you hit it twice, you will have a local axis. Hitting the same key a third time will reset the tool to its initial state… You can also select an axis with the MMB . As usual, LMB or ↵ Enter will confirm the transform, RMB or Esc will cancel it.

Skinning and Cloning Objects

Relevant fields highlighted in yellow.

For any type of objects, at the very top of the Link and Materials panel, you will find two fields, one in light pink and another right next to it in gray.

The field in gray starts with OB: and is the name of the Object datablock itself. It has to be unique within the .blend file across all scenes. The field name on the left starts with a two-letter abbreviation indicating what type of object it is, and the name of its skin, or physical appearance (an ObData datablock):

• ME: is the physical mesh, made up of vertices.
• CU: is a curve, surface, or text object, made up of control points.
• MB: is a metaball, whose skin is represented as a mathematical function.

Any of these skins can be shared by objects. Imagine a scene with 50 cats, some skinny, some fat. You would have two meshes, ME:Cat.Skinny and ME:Cat.Fat. You would create 50 OB:Cat.001, OB:Cat.002, …, OB:Cat.050, and assign 20 of the OBjects to be fat cats, and the rest skinny. For more info on duplicating objects and object data, see the duplication sub-part of this chapter.

Options

Clicking the F will fake a user of the skin, and it will not be deleted when no one uses it. The next time you open the .blend file, it will be in memory and will not have to be re-made. You can then create an object of its type, and use that skin.

At any time you can change the skin of an object by clicking the up-down selector on the left of the field and selecting a different skin for that same object type. When you do, the field will then show the multi-user button, “2” identifying how many other objects share this skin.

Note, however, that objects also have a “type”, i.e. you can’t assign a “curve” data to a “mesh” object, you cannot assign anything to an “empty” object, etc.

For more on all this, see the Data System chapter.