There are two styles of projections available for points and lines (and control points and control lines). The default style is to use renderings, as shown above. The rendering is well suited to surfaces and cylinders but it can be a bit slow (because each change to the view requires a full re-rendering of the 3D scene and a blending with the photograph).
If one is interested only in points, lines, control points or control lines (as some projects may not have surfaces at all), then there is a fast projection option. This option is set in the Image tab of Preferences - User Interface. When this option is chosen, and the projection visibility is set to match the chosen options or a smaller set, then only the fast projection method will be used. Selection will be faster, image scroll will be faster, etc. As soon as other projection visibility is turned on (e.g. surface, cylinder, curves projections) though the more complete (but slower) rendered projection system will come into play. Both the fast non-rendered system and rendered system can be used at the same time.
Here is a list of differences in the two systems:
|
|
Rendered |
Fast Non-Rendered |
|
Can project points, lines, control points and control lines. |
Yes |
Yes |
|
Can project edges, surface draw, curves, cylinders and surfaces. |
Yes |
No |
|
Speed of zooming and panning photographs. |
Slower |
Fast, if only it is on. |
|
All projection settings on Visibility on Photos pane’s Settings section. |
Work |
Do not work. |
|
Colors of projections can be based on the object’s Material. |
Yes |
No, fixed 16 color set. |
|
Accuracy of points and line end points. |
Good, depending on settings |
Best |
|
Accuracy of line middles with high lens distortion cameras. |
Good |
Does not account for lens distortion in line middle. |
|
Lines that have an end point behind the camera of the current photo still display in the projections. |
Yes |
No |