3 Altium Designer Step-by-Step PCB Design Tutorial.

The illustration below shows the possible snap points for this configuration as green crosshairs and the Snap Distance as orange areas. In this case, the crosshair will automatically be attached to the grid intersection point, which is less than 1mm away. For example, the Snap Grid is configured at 2.5mm and the Snap Distance is configured at 1mm. In certain cases, the Snap Distance value can be reduced (1/2 or 1/4 of the Snap Grid size), but it should not be larger than the Snap Grid size. In most cases, the Snap Distance value must be equal to the Snap Grid size to avoid placing objects outside of grid intersections. The General section of the Properties panel also allows you to set the Snap Distance at which the cursor will be automatically attached to the anchor point.

We recommend using a smaller grid size (e.g., 1mm) to draw the component symbols more accurately and precisely, and 2.5mm or 5mm grid (depending on the density of the schematic component placement) for the component placement and connections. The current grid size can be seen in the lower-left corner of the design space. The type of grids used depends on the unit of measurement selected in the Properties panel. You can set your own values on the Schematic - Grids page of the Preferences dialog (accessed by clicking the icon at the top right of the design space then navigating to Schematic > Grids). Right-click in the grid list of the measurement unit you need. By default, Altium Designer has preconfigured snap grids with 1mm, 2.5mm and 5mm grid spacing, which can be switched in any editor by pressing the G hotkey button at any time.

Altium schematic examples