Which command to set cplane to XZ plane?

I have a rectangle on an aircrafts port fuselage side, effectively in a XZ plane, I want the rectangle to be facing me in Front view, its not far off from doing so as it is.
setting cplane to 3 points allows pick of origin to lower left of rectangle, then pick of x axis along base of rectangle then , and this is where I am left wanting, it asks for y axis, yet I want to pick the z axis, the side of the rectangle.


Do you want a CPlane which is parallel to the Front view CPlane? If so go to the Front viewport, click on the arrow next to the CPlane name (“Front”), move the cursor over Set CPlane so that a menu appears, and select Set Elevation. Then either type in the amount you want to move the CPlane by, or go the Top or Right viewport and pick the location of the Front CPlane.

Hi David,
best explained with a mockup.

rectangle has been projected to fuselage skin. I need a Cplane which best fits the rectangle to Front view so I can take measurements of features within it in ‘Front’ view, and draw on it in ‘Front’ view.

As such I need A-B as X axis, A-C as Z axis. I have drawn a line 90deg rotat on A-B to represent where Y axis will be, so A-E is Y axis. I wouldnt have this line normally to work to.

Mockup fuselage rectangle Cplane task.3dm (73.8 KB)


Steve, are you trying to set the CPlane in the Perspective or Top viewport to get the desired alignment in the Front viewport? If so see if this gives you what you want.

In the Front viewport (not the Perspective or Top viewport) click on the arrowhead next to the viewport name so that the drop down menu appears. Then move the cursor over over Set CPlane in the menu. Select 3 Points and follow instructions, selecting A as the first point, B as the second point and C as the third point.

BTW, your line AE is not perpendicular to AC.

Hi David,

success (and ye E was made by rotating AC by 90deg in top view so I see its uphill a bit !

Am I right in saying that the viewport that you want the resulting Cplane to be almost same as the existing Cplane view is the one you select the Cplane change option in ?

e.g. If I had been looking at top of a pitched roof house in top view, then wanted the one pitched slope as cplane, I would have made that 3point choice in top view.

I selected the 3point option in the FRONT viewport, but then clicking ‘A’ it was grabbing the rectangle that sits out front of the fuselage. The only way to select ‘A’ was to select it in Perspective view, fearing that this would mess up the fact that I wanted the ABCD rectangle facing me in Front view, and feeling that all picks should be done now in FRONT view after making that option in that view, I went ahead anyway to see what happened, and it worked.

So if one selects a CPlane creation option in an ortho view, one can make the mouse clicks on the curves and points in perspective WITHOUT messing up the command.

Now if I had made that 3point choice in Perspective view, as I very often do, for in that view is where I best see the curves I need to select, then it never works out as expected.

At last, this is the breakthrough, knowing where to make the CPlane option and then which viewports one can make the selections in.

Venturing further, is one ok to make some of the selections in different viewports or must all then be made in just one ?


Good to hear your problem is solved.

You can should the CPlane in the viewport which works best for what you need to do.

You may want to explore the differences between “Standard” and “Universal” construction planes. The choice can be made in DocumentProperties > Modeling Aids or Options > Modeling Aids

> Standard construction planes

> The construction plane of each viewport is independent from all of the other constructions planes.

> Universal construction planes

> See also: SynchronizeCPlanes.

> The behavior of the construction planes in the viewports is linked. They all share the same origin and are positioned normal to each other. Moving, rotating, or otherwise changing the construction plane in one viewport, changes the construction planes in the other viewports, so the 90-degree/right angle/normal orientation of the construction planes is maintained.

> If a construction plane is defined in some view, the Front view for example, and Universal mode is enabled, then the construction plane that was defined will be the Front plane of the new universal plane.

[quote=“Steve1, post:5, topic:42351”]
Venturing further, is one ok to make some of the selections in different viewports or must all then be made in just one ?
[/quote] Why don’t you try and see what happens.