Manual/Editing Objects
From BlenderWiki
Contents[hide] |
Moving (translating) objects
Mode: Edit mode / Object mode
Hotkey: G
Menu: Mesh → Transform → Grab/Move (or Grab/Move on Axis for constraints)
Description
To translate an object is to place an object in Grab mode.
The selected objects will be displayed as white wireframes and can be
moved with the mouse (without pressing any mouse buttons); see (Grab mode). To confirm the new position, click LMB 
or press ENTER; to cancel Grab mode, click RMB 
or press ESC. The header of the 3D Window displays the distance you are moving.
Options
Axis constraint
| Note: For this section, and it sub sections, please reference (Global axes). |
Movement can be constrained to an axis that is aligned with one of the axes of the global coordinate system, centered on the object's original world location. The cube "B"'s original world location is labeled "C". The center of the global coordinate system is labeled "W"; the Z axis is not visible.
By constraining movement to a global axis you are, in effect, restricting movement to one dimension.
The global aligned axes are color coded as follows:
- X axis is dark red. Labeled "X axis".
- Y axis is dark green. Labeled "W-Y axis".
- Z axis is dark blue. Labeled "Z axis".
The restricted axis is always highlighted in a lighter shade of
color. For example, the Y axis is drawn in light green if movement is
constrained to the Y axis; labeled "Y axis".
There are two ways to constrain movement: using the mouse or using the keyboard.
Using the mouse
To lock or constrain movement using the mouse, enter Grab mode and move the object while pressing MMB 
. While in Grab mode you can use the Gesture System to pre-select an axis by moving the mouse in a direction roughly inline with a world axis and then clicking and releasing MMB . For example, if you move the mouse along what visually appears to be the X axis and then click and release MMB the object's movement will be restricted to the world X axis.
Alternately, you can interactively choose the constraining axis by dragging with the MMB while in Grab mode. All three axes become visible with a guide line that emanates from the object's original location; labeled "C". This guide is drawn in white dotted line labeled "S".
As the guide line nears an axis that axis becomes highlighted in a
lighter shade and the object snaps to that axis. In this example the
guide line is near the Y axis and the cube, labeled "B", snaps to it.
If you keep CTRL pressed while moving the object you will activate Snap mode, and the object will move by a whole number of units (grid squares). Snap mode ends when you release CTRL so be sure to confirm the position before releasing it. For finer snapping you can hold both CTRL and SHIFT.
You can control positioning to a finer degree by holding SHIFT while you move. Large mouse movements will translate into very small object movements, which allows for finer positioning.
The location of selected objects can be reset to the default value by pressing Alt G. The default location is the origin of the global coordinate system.
Using the keyboard
You can constrain movement to a given axis by pressing either X, Y or Z. A single key press constrains movement to the corresponding global axis (Global Constraint), as MMB does. A second keypress of the same key constrains movement to the corresponding Object local axis (Local Constraint) and a third keypress of the same key removes constraints, (No Constraint). The constrained axis is drawn in a lighter color to better visualize the constraint. (Local Constraint) and (Global Constraint) are all examples of constraints on the X axis using the X key.
 No Constraint. |  Local Constraint. |  Global Constraint. |
Once grabbing is activated you can enter the Object translation manually by simply typing in a number. This will change the 3D window header as shown in (Manual entry).
The number entered is a distance number (i.e. how far from the object's current location). Think of the "D" as in displacement, delta or distance. The number entered is not a world coordinate. To change the object's world coordinates see Transform Properties Panel.
By default the X component field is where entry initially goes; see field labeled "Dx" in (Manual entry). You can change the default by using the TAB prior to entering any numbers. For example, to translate 4.4 units along the Y axis you would:
- Enter Grab mode.
- TAB once.
- Type 4.4.
To translate 3.14 units on the Z axis you would use the TAB key twice prior to entering the numbers.
Currently you can't delete an incorrect number. You must restart by returning to the original numbers. The BACKSPACE key will reset to the original values. Hit ENTER or SPACE to finalize and ESC to exit. If you want more flexibility with manual entry see Transform Properties Panel
Hints
You must use the keyboard's "." not the numeric keypad's "." for decimals.
Rotating objects
Description
Change the rotation by moving the mouse and confirming with LMB or ENTER. You can cancel with RMB or ESC.
Rotation in 3D space occurs around an axis, and there are several ways to define this axis. But in general an axis is defined by a direction line and a point that the line passes through. By default the axis is orthogonal to your screen (i.e. it is going into or out of your screen). If you are viewing the scene from the front, side, or top 3D view windows, the rotation axis will be parallel to one of the global coordinate system axes. If you are viewing the scene from an angle, the rotation axis is angled too, which can easily lead to a very odd rotation of your object. In this case, you may want to keep the rotation axis parallel to the coordinate system axes.
Examples
As you rotate the object the angle of rotation is displayed in the 3D window header; 
.
Options
Axis of rotation Constraint
Just like Grab mode you can constrain the axis of rotation by using either the mouse or the keyboard. The only difference is that you only enter an angle. See Grab mode's Axis constraint for exact details.
Point of rotation
To select the point-of-rotation that the rotation axis will pass
through, use the Rotation/Scaling button accessed in the header of the
3D window, 
. This will display the (Pivot menu) .
- Active Object
- the axis passes through the active object (drawn in pink). See Selecting objects.
- Individual Object Centers
- each selected object receives its own rotation axis, all mutually parallel and passing through the center point of each object, respectively. If you select only one object, you will get the same effect as with the Bounding Box Center button. You can also select this by presssing Ctrl DOT.
- 3D Cursor
- the axis passes through the 3D cursor. The cursor can be placed anywhere you wish before rotating. You can use this option to easily perform certain translations at the same time that you rotate an object. You can also select this by presssing DOT.
- Median Point
- the axis passes through the median point of the selection. This difference is only relevant in Edit Mode, and the Median point is the barycentrum of all vertices. You can also select this by presssing Ctrl COMMA.
- Bounding Box Center
- the axis passes through the center of the selection's bounding box. If only one object is selected, the point used is the center point of the object, which might not necessarily be in the geometric center. You can also select this by presssing COMMA.
For finer control or precision use CTRL or SHIFT. Pressing CTRL switches to Snap mode and rotations are constrained to 5 degree increments. Pressing SHIFT at the same time contraints the rotation to 1 degree increments. Pressing SHIFT alone while rotating allows finer degrees of rotation as precise as 1/100th of a degree. The rotation of selected objects can be reset to the default value by pressing Alt R.
If you're just getting started with rotation, don't worry too much about the foregoing details. Just play around with the tool and you'll get a feeling for how pivot points effect rotation. For example, an easy way to understand how pivot points work is to create two cubes as shown in (Multiple Selected). Then cycle through each pivot point type while in Rotate mode.
Hints
To have one cube orbit another cube set the pivot point to Active Object. As you rotate, constrained or not, the other object(s) orbit the active object.
Scaling objects
Description
Scale the objects by moving the mouse and confirming with LMB or ENTER, and cancel with RMB or ESC.
Scaling in 3D space occurs around a center point; much like a rotation occurs around a pivot point. If you increase the size of the object, all points are moved away from the selected center point; if you decrease it, all points move towards this point.
Options
Axis of scale Constraint
By default, the selected objects are uniformly scaled in all directions. To change the proportions (make the object longer, broader and so on), you can lock the scaling process to one of the global coordinate axes, just as you would with Grab mode and Rotate mode. Again all considerations on constraining to a specific axis, in respect to Grabbing, still hold as well as those on numerical input. See Grab mode's Axis constraint for exact details.
Center point of scale
To select the center-point-of-scale use the Rotation/Scaling button accessed in the header of the 3D window, . This will display the (Pivot menu) as shown in Point of rotation.
Here again the CTRL key switches to Snap mode, with discrete scaling at 0.1 steps. Press SHIFT for fine tuning. The scaling of selected objects can be reset to the default value by pressing Alt S.
Mirroring objects
Mirroring objects is a different application of the scale tool. Mirroring is effectively nothing but scaling with a negative factor in one direction. For example, to mirror in the direction of any single axis:
- 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
|
