King Louie Posted August 25, 2016 Share Posted August 25, 2016 I have an in-house engineer (not a drafter/detailer) that wants to draw some stuff up in 3d for his reference. He wants to know if there is a way to "invert" the z-axis, so that when he inputs relative reference points (x,y,z), the z-axis will work "backwards", i.e. positive z is "down". He has tried the various UCS adjustments, etc., and that is not what he is looking for. All he wants is for away from him to be positive z and towards him to be negative, as if he is inside a building looking up at the ceiling. Ideas? Quote Link to comment Share on other sites More sharing options...
eldon Posted August 25, 2016 Share Posted August 25, 2016 Draw it all in normal 3D. Then take a front view, draw a horizontal line from 0,0 and mirror everything about that line. Quote Link to comment Share on other sites More sharing options...
Dadgad Posted August 26, 2016 Share Posted August 26, 2016 Draw it all in normal 3D. Then take a front view, draw a horizontal line from 0,0 and mirror everything about that line. +1 good one eldon, spot on. Quote Link to comment Share on other sites More sharing options...
SLW210 Posted August 26, 2016 Share Posted August 26, 2016 Just draw with Bottom View Active instead of the usual Top View. Quote Link to comment Share on other sites More sharing options...
lrm Posted August 26, 2016 Share Posted August 26, 2016 I found this a curious question. If the need is to have the Z axis going away from when viewing an orthographic view then the obvious approach would be to use the BOTTOM view as SLW210 suggests. However, when viewing the bottom view the WCS X axis is to the left and the Y axis points up. This may be undesirable to the OP. If the “in-house engineer” wants and orthographic view in which the X axis points to the right, the Y axis points upwards while the Z axis is pointing away from you then the user is requesting a left-handed coordinate system. I think all engineer applications text books, etc. (there may be an exception) use right-handed coordinate systems. Most AutoCAD commands assume a right-handed coordinate system. The only AutoCAD exception to the RHR convention that I can think of is the 3DROTATE command about the Y axis. It assume a left-handed coordinate system while the X and Z axis rotation use the convention right handed convention. Try it out! ~Lee Quote Link to comment Share on other sites More sharing options...
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