To create a curve we can use two commands:
- Create -
- Create -
Both command create the same type of curve, but the way you draw them is different. You will mostly use the EP curve, as it will run through the points you specify. In most cases that is the most convenient way to draw a curve.
When using the CV tool, you'll specify the locations of the Control Vertices (which act like 'weights' that pull the curve into a curvature; the curve does not run trough them).
The degree can be adjusted by clicking on the rectangular box next to the command. An option box will open where adjustments can be made regarding the activated command.
When accuracy is required, there are several optional methods to assure accurate construction of curves:
- Activate the grid snap option to snap to grid points.
- Activate the curve snap option to snap to a curve( activate snap, press mouse button and hold whilst dragging along the curve).
- OActivate the point snap option to snap to a corner of a curve( first activate the display of the corner points - Display - Nurbs - Edit Points , activate snap, press mouse button and click on corner of curve).
- Enter the absolute or relative coordinate of the next point of the curve. (Activate the curve command and define the first point, type in the absolute or relative coordinate of the next point)
When you create a closed curve, you draw the last edit point (EP) on top of the first one, with either point- grid- or curvesnap. Or after creation move the last control vertex (CV) on the first one. This may seem strange, but using this methode results in less problems when using the curve in, for example, a loft action. This methode is absolutely not ment for polygonal modelling.