BLINK Design Posted November 20, 2008 Share Posted November 20, 2008 OK, I am experiencing a brain freeze! All isometric views in VW default to 45-45 degree views with respect to a vertical z axis. In the viewports, you can select CUSTOM VIEW and then the window (attached) comes up. A simple 15 degree rotation along the Z axis is desired and I cannot manage this. Any suggestions would be appreciated! Quote Link to comment
mike m oz Posted November 20, 2008 Share Posted November 20, 2008 What you have shown is Isometric projection and the two angles are actually 30-30. What you want is Trimetric projection. This projection is not available in VW. More information here: http://en.wikipedia.org/wiki/Axonometric_projection Quote Link to comment
BLINK Design Posted November 20, 2008 Author Share Posted November 20, 2008 Mike hi and thanks for the answer. It seems I was not having a brain freeze afterall but rather there is some confusion about geometry. A 30-30 is not possible given that the three angles must equal 180 degree including the 90 degree object. What is even more curious is that the description on wiki is wacky! An ISOMETRIC is when all three axes are the same relative to the picture plane. That's 45-45 as well the object is tipped forward 45 degrees so that you can better see the top. An DIMETRIC is when two axes have equal angles and a TRIMETRIC is when all three angles are different. These are all called Axonometric drawings and all are scalable. There is no foreshortening as with perspective! The solution is to rotate the original object on the design layer 15 degrees and then use the standard ISO views that are are available. The projection IS AVAILABLE in Vectorworks! Thank me for my help. Wink! Quote Link to comment
mike m oz Posted November 20, 2008 Share Posted November 20, 2008 The attached image has objects 1500 sq with an extrusion height of 3000. - The first object is orthogonal and in a standard isometric view the angles are 30? and 30?. - The second object is rotated 15? and in a standard isometric view the angles don't match 30? and 60?. Quote Link to comment
BLINK Design Posted November 21, 2008 Author Share Posted November 21, 2008 Mike, the view is oblique. You must measure the angles from a plan view and if you do you will find they are 45 degrees and not 30 degrees. Further, one way to know they are 45 degrees is that your front and rear vertical edges are aligned. Remember that in a 45-45 triangle, the length of the two short sides are equal. Yet another way to know is that with a circle you have 360 degrees so all of the angles above the line (one half of a circle), must total 180 degrees. You know that the object is 90 degrees so the other two must equal 90 degrees as well. 90 + 30 + 30 = 150 degrees which is incorrect. These objects are essentially elevation (flat) of a tilted object, thus the distortion between the object (relative) and the ground (absolute). Tilt any object towards you in real space and time, you will see the the angles cannot be measured as you have shown them. Quote Link to comment
Morgan Pileggi Posted November 22, 2008 Share Posted November 22, 2008 Blink you are confused. the actual object has a 90 degree corner, but the corner is not 90 in the isometric views (30+30+120 = 180). the advantage of the isometric view is that all the line lengths are correct, but this is only possible if the angles are 'incorrect' Quote Link to comment
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