When drawing a Line spline or Wall object, Ortho Snapping Mode constrains line creation to the horizontal or vertical directions relative to the active grid. That
is, with Ortho on, you can draw only lines that are parallel to lines of the active grid. Ortho is particularly useful for
drawing plans where all lines must be at 90 degrees to each other, such as a house plan. To constrain line-drawing to other
angle increments, use Polar Snapping Mode instead.
Important: By default, Ortho Snapping Mode is not directly accessible in the 3ds Max user interface. To add it as a button on the Snaps
toolbar, follow this procedure.
Ortho Snapping applies primarily to the creation of line splines and wall objects. It can be used while creating other objects,
but results are likely to be unsatisfactory.
Ortho mode displays a compass which gives a readout of the current angle of the input relative to the positive direction of
the local X axis.
Note: If you hold down the Alt key in Ortho mode, the next point becomes doubly constrained by both the previous point and the first point of the current
object. This allows you to close splines precisely. In this mode, two compasses are displayed; one each at the first and previous points.
To add Ortho Snapping Mode to the Snaps toolbar:
Open the Snaps toolbar, if necessary. To do so, right-click an empty part of the main toolbar, such as the area directly below
one of the drop-down lists, and choose Snaps.
Drag the right end of the toolbar to the right to make room for a new button.
Choose Customize menu > Customize User Interface.
This opens the Customize User Interface dialog.
On the dialog, click the Toolbars tab.
Scroll down the Actions list on the dialog to the Ortho Snapping Mode item. You can jump to the O section by clicking any
item in the list and then pressing O on the keyboard.
Drag the Polar Snapping Mode item from the list to the empty section of the Snaps toolbar. This adds the button to the toolbar.
Close the Customize User Interface dialog.
3ds Max automatically saves the toolbar in its revised state and makes the new button a permanent part of the user interface.
To use Ortho:
Turn on the Ortho Snapping Mode button.
The button appears depressed.
Begin to draw a Line spline.
An orange compass appears where you place the first point, along with a red number indicating the angle of the current line
segment with the positive direction of the local X axis.
Move the mouse cursor around in the viewport.
The line jumps to 90-degree angle increments on the local X axis, while the compass reading updates to show the current angle.
Click to place the next vertex.
Repeat steps 3 and 4 until you're ready to complete the shape.
Do either of the following:
To finish the shape at the most recent vertex without closing it, right-click anywhere.
To finish the shape by closing it, position the mouse cursor close to the first point and then click. A small dialog opens
asking if you want to close the spline; click Yes.