Second Life Build Tutorial: Position, Rotate, Stretch
![position a object](build/position.jpg)
Once you have created a object, you can stretch it or change its position, orientation, texture, etc. Click on the “Edit” button in the build dialog. (Note: After you have created a object, you are automatically switched to the Edit pane.)
![the edit pane](build/edit.png)
The Edit button lets you position, rotate, stretch your object, or change its texture.
Let's click on Position. Then, your object will have a red, green, blue arrows on it. The red line is the x-axis, representing West/East line, with the arrow pointing to the positive side (East). The green line is the y-axis, representing South/North line, and blue is the z-axis representing up/down. You can then drag these arrows to position your object.
![rotate](build/rotate.jpg)
Try the various radio check-boxes for Position, Rotate, Stretch.
Snap to Grid
In the Edit mode, there is a “Use Grid” checkbox. When checked, it automatically snaps to the nearest ruler division when you are positioning it. It also works for rotation.
![grid options](build/grid_options.png)
About The Coordinates (about Ruler Mode)
![ruler mode](build/ruler_mode.png)
Ruler mode: World = absolute coordinate
Notice there's a “Ruler Mode” menu in the Edit pane. You have these choices: World, Local, Reference. These choices give you 3 systems of coordinates orientation. By default, it is World, meaning that the coordinate axes is oriented the same way as the world's grid. The x-axis is the west/east, the y-axis is the south/north, and the z-axis is the down/up, ALWAYS. When the ruler mode is World, you can consider it as the absolute coordinate system.
To understand the World coordinate: create a cube and select it. Now, turn your avatar to face the same direction the y-axis arrow is pointing to. Now, turn on your mini-map. You will see that you are facing north directly. (When the Ruler mode is World, you can rely on the arrows as the absolutely correct compass)
Ruler mode: Local = coordinate intrinsic to the object
Now, suppose you just made a cylinder. Now, tilt it a little bit (using the Rotate radio box). Now, you want to move this cylinder parallel to its circular wall (the cylinder's directrix). In this situation, you want a coordinate system oriented such that the z-axis is coincident with the cylinder's directrix. Because, this way you will only have to change the position of the cylinder in only one coordinate -- the z-axis. This is the option “Ruler mode: Local” is good for. Basically, each object has a intrinsic coordinate orientation, and you can position a object relative to this intrinsic coordinate. When you rotate/tilt a object, the intrinsic coordinate rotate/tilt with it. So, for example, if you create a cylinder, and tilted it a bit, and the intrinsic z-axis will tilt with it. So, when you want to move a cylinder “up” in the direction of its top cap, you can set the “Ruler mode” to “local” and do this easily.
Ruler mode: Reference = user defined coordinate orientation
Suppose you are building a house facing 30°. You need to put build and position furniture inside the house. It would be nice, if the xyz-axes are parallel to your house's walls. This would make positioning things much easier. This is when you need a user-defined coordinate orientation, and is what the “Ruler mode: Reference” is for.
To test this reference ruler mode, try this:
Create a cylinder. Tilt it a little bit. Now, select the menu [Tools ▸ Use Selection for Grid] or press shift-g. This will set your current selected object's intrinsic coordinate orientation as the reference orientation. Now, create a cube. Now, set the ruler mode to Reference. You will now see that the position/rotation etc are using the cylinder's intrinsic grid.
Moving Objects Freely
![move](build/move.png)
The move button allows you to move objects in a free way.
You have the position tool that moves the object in the direction of the coordinate axes. But sometimes you just want to grab a object and move it freely. This is done with the Move button.
Technically, what happens in a free-move mode is that, the object is constrained to move on the xy-plane. Forward/backward/left/right movements of the mouse will bring the object farer/nearer/left/right with respect to the view point (the camera).