New 3D user has questions about 3D views
A couple months ago, we transitioned from Autocad LT (2D) to BricsCAD Platinum at work. (We've only ever had 2D CAD programs here.) I remember fooling around with the 3D tools for an hour or two, and getting very frustrated. I've been doing 2D drawings ever since. I decided it is time to bite the bullet and learn the 3D. The first big issue is my confusion over views. If you use a drawing wizard, to start a 3D drawing, it lays down a nice inclined grid on a pale blue background. What I call the initial view. And I can make some basic shapes on that grid and extrude them. But I don't understand how to move around in 3D space without getting confused. I've used the "LOOK FROM" toolbar, but it's not really obvious what it is doing. Are the "LOOK FROM" tools always relative to the initial view? Or are they relative to the current view? Also, I'd like to know how to get back to that 'initial view", because none of the "LOOK FROM" tools seem to take me there. Granted, I can always undo, but I need to know how to draw on any face of my project, and then get re-oriented and back to where I began.
Can someone help me with this?
Can someone help me with this?
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You can move around the model in several different ways by dragging the mouse while holding down the wheel, either alone or in combination with holding down the Shift, Ctrl, or Alt key.0
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What I most want to know is how to get back to the initial presentation with my object sitting on the grid. And I am getting confused about what face of the object I am looking at, especially if I haven't placed any holes, cutouts yet.0
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The Look From views (menu and toolbar) are relative to the WCS, not the current UCS if you're using one.
The "front left" view is nearly the same as the one that the wizard drops you into when it starts a new 3D drawing.
One way that is easy to get lost is when UCSORTHO is set. This causes the UCS to follow the Look From view when selecting top/front/left, etc. so that the plane of the screen is parallel to the UCS's X-Y plane. Sometimes this is a very handy shortcut (I usually leave it set) but occasionally it can get in the way (especially if one isn't expecting it).
There's also dynamic UCS (DUCS (status bar) or UCSDETECT (settings) or F6) that flips the UCS to be parallel to a hovered-over face. Very handy when working on inclined surfaces but also useful for more rectilinear objects. Again, though, an unexpected change in coordinate systems can be disorienting.
For general orientation, I visualize TOP/BOTTOM as looking at the object's top/bottom (X-Y plane is the ground) and FRONT/BACK as viewing the object's front or back. I don't worry too much about the noun names of the other views.0 -
Thank you Richard.
If I understand you correctly, the moment I select a face of my object, and "ALIGN UCS", I have lost the reference for the "LOOK FROM" commands. Wierd. In the 10+ years I've been doing 2D drawings, I've never even thought about the WCS. Because of the nature and hole count of my designs, I place a lot of ordinate dimensions on my third angle projections. To create the 0,0 datums (reference point) for the ordinate dimensions I use the "UCS - ORIGIN" command. So I'm nearly always operating with a UCS.
Is there a way to return to the WCS, so I can get back to the initial 3D view?
I checked and "UCSORTHO" is active. Must have been the default, because I never set it. I will experiment with turning it off, and try "DYNAMIC UCS", also.
Pushing 60 and I sometimes think I am getting too old to learn this stuff.0 -
Thank you Richard.
If I understand you correctly, the moment I select a face of my object, and "ALIGN UCS", I have lost the reference for the "LOOK FROM" commands. Wierd. In the 10+ years I've been doing 2D drawings, I've never even thought about the WCS. Because of the nature and hole count of my designs, I place a lot of ordinate dimensions on my third angle projections. To create the 0,0 datums (reference point) for the ordinate dimensions I use the "UCS - ORIGIN" command. So I'm nearly always operating with a UCS.
Is there a way to return to the WCS, so I can get back to the initial 3D view?
I checked and "UCSORTHO" is active. Must have been the default, because I never set it. I will experiment with turning it off, and try "DYNAMIC UCS", also.
Pushing 60 and I sometimes think I am getting too old to learn this stuff.0 -
Just some additional hints:
- switching to 3dcontext gives you an isometric view of your model initially , you could recreate such a view by typing "VPOINT" "1,-1,1"
- if you want to save a view to get back to it later, type "-VIEW" "S" and a name of your choice. Provided UCSVIEW is set to on, restoring the view (by typing "-VIEW" "R" "yourname") will also restore the coordinate system that was in effect when the view was created. You may bind these commands to a key combination, if you so like.
I personally think that all the newer ucs-functions (UCSFOLLOW, UCSORTHO, UCSDETECT) can safely be ignored, since they add further complexity where the plain old UCS command already had all you need. I bet they have been created primarily for users expecting a certain behavior they know from other programs.0 -
If I understand you correctly, the moment I select a face of my object, and "ALIGN UCS", I have lost the reference for the "LOOK FROM" commands.
No (at least assuming I'm understanding the interrelationships correctly). The Look From commands are always with respect to WCS, so even with a current UCS set to a face, you'll Look From with respect to the world coordinate system. However, if UCSORTHO is ON then a Look From can cause you to lose the face-aligned UCS.
Wierd. In the 10+ years I've been doing 2D drawings, I've never even thought about the WCS. Because of the nature and hole count of my designs, I place a lot of ordinate dimensions on my third angle projections. To create the 0,0 datums (reference point) for the ordinate dimensions I use the "UCS - ORIGIN" command. So I'm nearly always operating with a UCS.
Is there a way to return to the WCS, so I can get back to the initial 3D view?
UCS - ORIGIN should (AIUI) only translate the origin, not rotate the coordinate system, so it won't rotate the axes of a face-aligned UCS. Also, you can return to the global WCS quickly by UCS - World if desired.
I checked and "UCSORTHO" is active. Must have been the default, because I never set it. I will experiment with turning it off, and try "DYNAMIC UCS", also.
Pushing 60 and I sometimes think I am getting too old to learn this stuff.
Just play with it some on a non-critical drawing. It's fun! And I doubt that you're too old -- I'm looking at 60 in the rear view mirror. ;-)0 -
Oops, I have to correct myself (#7) - totally forgot that I redefined the 3dcontext command in order to prevent my machine from crashing - the original 3dcontext seems to define an initial vpoint of 70,-130,80 (not isometric).0
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Thanks Knut. How did you determine the 3dcontext command defines an initial viewpoint of 70,-130,80?0
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just by invoking 3dcontext and vpoint right afterwards - the current viewpoint is listed as default (in the commandline).0
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