Scale on an angle

[ThomasSkye]

HI all.

I am drawing an elevation of a house with the extension projecting at an angle from the back.  How do I draw the windows so they are the correct size.  There are in green on the screenshot but I can't figure out how to get them to the correct size on the angle.  The velux should be 1200 wide x 1300 and the wall window should be 1200 wide x 1500.

[CyberAngel]

The easiest option is probably to change your UCS to match the wall.

 

If you're using an isometric view, though, it gets a little tricky. In other words, you're trying to draw a surface, such as this wall, to look the way it would if you're not seeing it directly from the front. Perspective gets involved, so it's not possible to draw everything to the exact scale.

 

The typical workaround is to draw horizontal lines at 30 degrees offset from normal, while keeping the vertical lines vertical. You can keep the distances the same. If that doesn't work out, please provide more information about what you're trying to do.

 

Welcome to the forum.

[lrm]

@ThomasSkye what you've drawn is commonly consider an oblique projection where one side of a 3D object is drawn head-on and undistorted while other sides of the object are drawn at a constant angle. The scaling in the third dimension may be the same as the  front side (Cavalier projection) or may be foreshortened (Cabinet projection).  To properly scale lines on planes not parallel to the front plane it is necessary to determine the x, y, z' components of the lines where the z' axis is the oblique angle you have chosen (roughly 20° in your drawing).

Check here for more info on oblique projections.

[BIGAL]

I drew it true size as a ortho, then made it into a block and changed X scale.

 

 

There are ways to draw in 2d and make into what looks like 3d Using Rotate3D.

Edited February 2 by BIGAL