Tutorials CivilCraft help Walkthroughs
Open a DWG or DXF as linework
Open a drawing's linework on the plan, layer by layer, and use its contours, 3D polylines and closed outlines for the surface.
Written for CivilCraft 0.4. The same help is inside the app: press F1.
A topographic survey often arrives as a drawing: contours as polylines at their elevation, breaklines as 3D polylines, the site outline as a closed polyline. CivilCraft opens the drawing's model space as layers on the plan, and can turn those lines straight into the surface.
Open the drawing
- Click Linework in the Surface group (or Open, or drop the file on the plan) and choose a
.dwgor.dxffile. The drawing is read on this computer; nothing is uploaded. DWG from 2000 to 2018 and ASCII DXF are read. - The Linework dialog lists the drawing's layers that hold lines, closed shapes or points, and whether they have elevations. Layers that are off in the drawing start unticked. Text, hatches, dimensions and other objects that are not linework are counted and left out (the dialog says which).
- Check Drawing units. When the drawing says its units, CivilCraft converts them into the project's (millimeters into meters, meters into feet, inches into feet). A drawing in feet is read as US survey feet without scaling: the two differ by 2 parts per million, and scaling state plane coordinates by that would move them by feet. When the drawing does not say its units, its numbers are read in the project's units; pick the right units in the list if they are not.
- In Use for the surface, choose what each layer gives the surface (or leave Only show it). Layers named like contours (TOPO, CONT, CNTR) that have elevations start as breaklines.
- Click Add. The layers appear under GIS layers in the left panel; each use is put into the surface. Every part is a step of its own: ⌘ZCtrl+Z takes them back one at a time.
What each kind of layer can give
| The layer holds | Use for the surface |
|---|---|
| Contours (polylines at an elevation) | Breaklines at the lines' own elevation, or at the ELEV field |
| 3D polylines | Breaklines at their own elevations |
| A closed outline | The surface boundary (the largest closed shape, or the one you selected) |
| Points with an elevation | Survey points, described with the layer name |
| Lines at elevation 0 (plan linework) | Nothing: it stays on the plan as a base drawing |
Later, use Use for the surface in the layer's menu under GIS layers to do the same for a layer you only showed.
How the drawing is read
- Arcs, circles, ellipses, bulged polyline segments and splines become short straight pieces (every 5° at most).
- Block references are drawn where they are placed, nested blocks too; what a block holds on layer 0 takes the reference's layer.
- Objects drawn in another plane (a different extrusion direction) are placed in world coordinates.
- Each object gets three fields: LAYER, TYPE (the object type) and ELEV (its elevation when all its points share one).
- Coordinates are taken as they are: the drawing must use the same coordinates as the project (for example the same state plane zone). Linked drawings (xrefs) are not opened: open them on their own.