Metric 2D/3D
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I think this is quite simple, but after some thought I just got confused and need some accurate answers.
Under Preferences | Template | Drawing Template I usually have Metric Millimeters-3D selected. Just to see what it was about, I checked out Metric 2Dwith the thought it would only allow the X and Y axes, but it seems I can still use the Z axis. So then I started thinking: when using 3D you are in "full 3D", and when using 2D you are in "2-dimensional 3D" (as if on flat paper, like how I'd draw a simple 3D sketch with measurements on a piece of paper ignoring depth precision (or horizon?), to put it like that)?
Anyway, whatever the answer, I've gotten obsessed now with this thing, so I must know... What is the exact difference between 2D and 3D modes? And what are the advantages and disadvantages?
Thanks.
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The 2d mode isnt really 2d (as you spotted) its just a change in the camera viewpoint. i.e. its like looking straight down on the model. Ive got a feeling it also changes the camera mode to parallel projection, although im not certain on that.
Those are only true when you load up a new file, though, as they can be changed very easily within SU when you get modeling.
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@remus said:
The 2d mode isnt really 2d (as you spotted) its just a change in the camera viewpoint. i.e. its like looking straight down on the model. Ive got a feeling it also changes the camera mode to parallel projection, although im not certain on that.
Those are only true when you load up a new file, though, as they can be changed very easily within SU when you get modeling.
Just to be certain I understand you: by parallel projection (which I take literally without knowing or remembering exact terminology) you mean, indeed, the ignoring of depth (and such), the literal precise parallel placement of lines which is how we see this back on-screen in 2D mode? Hmm, it has to be. What other reasonable possibility is there?
Is there a (significant) difference in resource use regarding the two modes?
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If you were to draw a box in parallel projection (with a pencil and paper) all the edges would be the same length on paper. If you were to draw it in perspective edges further away would be drawn smaller to give the impression of distance. This is the same in SU, so you are right.
I can see no reason why there would be a rise in the use of system resources, nothing extra is being displayed/calculated.
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You can change perspective mode to parallel projection any time "on the fly" under the Camera menu. Try playing with it to see the difference.
I myself tend to use perspective mode most of the times as it feels much more "naturalistic" to me. However parallel projection is handy sometimes;
- when you want to export images of "standard views"
- when you want to print to scale (well it is a "must" then - it won't work otherwise)
- when modelling, for very precise selections (when there are other pieces of geometry very close to what you want to select with the selection box) etc.
The 2D and 3D templates do not really differ from each other. I have the feeling that when there was no Google involved in SU there wasn't even a "3D" template because most of the "old users" tend to use a template more similar to the ones that are called "2D" now (this needs some confirmation from the "oldies" however).
So 3D templates give you more sense or feel of 3D space while 2D templates are more just another way - looking straight down lets you quickly draw a plan from scratch that you can develop into a 3D model later.
In reality, there is no difference between them.
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Thanks, guys. You've made it very clear and easily understandable.
There' still some questions. For instance: if there is no significant difference between 2D and 3D templates, why include a 3D template? Rotating the view in "2D" (when starting from the top view) quickly gives you the view you initially get in the 3D template. Also, the fact that a Z line is at your cursor is immediately strange when one expects 2D.
If I were Google, I'd remove the redundant "3D" templates, and install a TRUE 2D template with only X and Y, and call the current "2D" template the standard view or something like that. Or, even better, only keep the standard view (the current 2D template, and rename it), but give the option to deactivate the Z axis, so it's true 2D. Too many options, especially if redundant, only confuse.Regarding Perspective and Parallel views, I am under the impression that Parallel view uses less resources, because the sense of depth/perspective is not calculated, much like I would also calculate less or do less effort if I did not draw any perspective on paper.
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What Remus says.
It's just a matter of taste who is using which template I presume. You can even create your own template (like I have my own as well - or actually, I have several custom templates) and name them whatever you want.
These are just some pre-made "default" templates to begin with.
as for the two modes and using resources - I'm not sure it is like that but maybe.
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SU is used by a lot of different people, and its all down to preference really. As gai said a lot of the more traditional CAD types start with a 2D top down view, as thats what their used to. Although a lot of people new to SU might find it a bit confusing, so they use the default 3D template instead.
As for making a proper 2D template, SU is a 3D modeling program, so im not really sure why youd want to do any 2D stuff in it. There are much better tools for this.
Interesting point about perspective vs parallel projection. I hadnt really thought about it like that before. I wonder how much of a difference it makes to real world performance?
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My purpose was now more that of honest critique on the program I guess. I figured the program would be more consistent.
Having two differently named options that are essentially the same is odd. It's like having the choice between two coffees that are given interesting sounding names, but the simple truth is that one has slightly more sugar and it's hardly a difference, yet there they are those options.
It's not just odd; it's even wrong: 2=2, 3=3, 2#3, all true, yet it seems that in the program "2=3" (to put it simple like that, regarding the naming and what you get).
If it is true the two modes have no significant difference other than starting viewpoint, that human characer (Bryce?), and other little touches (like distant horizon), then one mode -- starting in standard 3D view, because this program is primarily concerned with 3D, and for those who need immediate sense of direction or familiarity -- would be enough, even more optimal, with the option to switch on/off the third axis (and all its related geometry), because when expecting 2D one expects 2D, and when expecting 3D one expects 3D. Simpler, cleaner, and more elegant than this fine program already is !
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Maybe I'm just used to it so I don't find it confusing.
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There do seem to be some technical differences between 2D and 3D templates, beyond simply the starting angle of view...but I can't elaborate. For now, just go with whatever floats your boat.
Gai is right, in early versions all the default templates, whether Imperial, metric or metric inches etc. all opened in plan view with no ground, sky or Flat Bryce. The Isometric/Perspective view came along later; that is, after all, how most other modellers open by default...at least they do when not in quad view.
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