CAD Import : Post import options

Units of length in CAD model

Extents of the CAD model: Specifies the geometrical bounding box extents of the AutoCAD model. There are no units for the extents, and this is provided merely to provide a cue to what the model units could be.

Suggested units of length

This is the unit of length guessed by GSA.

Units of length and Position of the model

Import units of length: Specifies the unit of length chosen for importing the drawing.

Note: If the units selected do not correspond to the units in which the drawing was made, import may not behave as expected. For example, if a CAD drawing of a roof truss is in meters, and it is imported in mm, the element sizes could be too small in the GSA model and/or the nodes can get collapsed since they would be too close to each other.

Shift the origin of the model to…: Specifies the coordinates of the new origin (in metres, with respect to the CAD origin) which all model coordinates are transformed to. When the origin is shifted a grid plane is created at the CAD origin, enabling coordinates to be viewed with respect to the CAD origin, despite the shift in origin.

Importing CAD models created with coordinates that are offset a long distance away from global origin results in nodal coordinates with high order of magnitude. This can lead to rounding and precision errors. To avoid such a situation, the coordinates can be transformed to a point closer to the model. (In determining whether the model is offset away from the global origin, GSA only uses entities from the layers selected on the ‘Select Layers to Import’ page.)

Rounding Tolerance

Same as rounding tolerance.

Connect 1D elements

Same as Connect 1D elements.

Auto Offset

Sets element offsets for horizontal beam elements automatically.

Coincident nodes

Sets tolerance for collapsing coincident nodes. See collapse coincident nodes.