Geometric Constraints

The Drawing Constraint functions allow you to quickly draw items with some conditions, such as parallelism, defined angle or intersections. The Input Fields on the Input Bar allow you to enter the coordinates of drawing points and the geometric dimensions of the objects, like length and angle.

Constrained Directions

Linear or polygonal graphic objects such as lines and Poly-lines, rotated rectangles, hatches, arcs and ellipses by radius and diameter, dimensions and walls, can be drawn aligned with one of the Cartesian Axes or rotated by steps of 15 degrees: to do this, just press the Shift key while moving the pointer.

Constrained Parallel, Right-Angle and Aligned/Tangent

These three buttons on the Input Bar provide the Right-Angle and Parallel constraints and the Intersected condition.

Constrain Parallel (P) and Right-Angle (R)

These conditions can be activated anytime with any tool or editing function and will affect the direction of the current movement.

To activate the Right-Angle or Parallel condition:

  • After the first click of the current operation you are performing, click the button corresponding to the desired condition or press its keyboard equivalent (P or R);
  • Click the reference object, e.g. the line you want to draw perpendicular or parallel to (the mouse-cursor changes to a pointing hand when on a valid object);
  • To cancel a condition, press the Esc key on the keyboard.

Constrain Aligned/Tangent

This condition constrains the pointer to intersect a reference line or circle, extending the line you are drawing to the intersection point, even outside the segment bounds, or constraining the direction to the tangent. 

To activate this condition, click the button in the Input Bar or press its keyboard equivalent. If the condition is activated before the start point is defined, it constrains the start point to be aligned to the line or tangent to the circle. If activated after the first click, it constrains the end point. 

The same result can be achieved by pressing the Command key + click on the datum line while drawing the line, polygon, wall or hatch/fill. 

The Constrain Tangent option can be activated to construct a line tangent to an arc or circle, either from the starting point or to the end point. 

To construct a line tangent to an arc or circle from the start point: 

  1. Activate the Constrain Tangent option.
  2. Click on the reference arc or circle. As you move the pointer, the start point of the segment will keep the tangent condition that is closest to the clicked point.

To construct a line tangent to an arc or circle on the end point: 

  1. Click to define the start point of the line. 
  2. Activate the Constrain Tangent option. 
  3. Click on the reference arc or circle. 

The drawing constraints and the snap options can also be displayed as grouped in a floating window you can move to a convenient position on the screen. To show this option, select “Snaps” on the Window menu.