Time is changing fast. Global warming was a scientific phenomenon for many a decade ago, but now its effects have arrived at everyone’s door step. In 2006 (AUGI HotNews March 2006 "From 2D to 3D: Conversion Techniques") I was talking about conversion of 2D objects to 3D solid objects. Now it is 2007 and I will be discussing 3D solid to 2D objects conversion techniques. Both techniques are adding advantages to solid model building. In this article, we will exlore the Flatshot command available in AutoCAD 2007.
You can draw a parallel between a camera shot of a building and a Flatshot technique. A camera captures the 3D image of a building (or any object) and projects it on flat film/paper surface to produce a nice 3D effect. The Flatshot command in AutoCAD produces a flattened view of 3D solids. The flattened 2D view is generated by projecting visible and hidden objects on the current XY plane. The projected 2D is created in the form of an auto numbered block, which you can rename logically using the Rename command.
Someone asked me, "Why should I upgrade to AutoCAD 2007?" My flat answer was "Flatshot." I am not exaggerating when I say that Flatshot has motivated me to start conceptualizing a new project directly in 3D, without drawing a single line in 2D. In the next five minutes, you will be with me.
Flatshot can be operated through the command line or accessed through the icon available in the "3D Make Control" panel of the Dashboard.
Figure 1: Dashboard
The Flatshot command leads you to a dialog box with three main sections, namely, Destination, Foreground lines, and Obscured lines. Flatshot produces 2D objects by inserting a new block, or you can replace an existing block, or 2D objects can be stored in a separate file. If you opt for a separate file for a Flatshot block, by default the name of the file produced will be new block.dwg or new block.dxf. The Destination section contains block creation options and the other two sections take care of selection of color and linetypes of the foreground lines and obscured lines.
Figure 2: Flatshot Dialog Box
Let's try to understand the usefulness of this wonderful command. We will take a live example from an actual project. The 3D model of a bungalow is developed in AutoCAD using solid modeling objects. The 3D model is good enough for the client to understand the planning concepts and visualize the aesthetic beauty of project before construction. So far as detailing is concerned, 2D is still king. Would you be happy if you can develop 2D Plan, 2D Elevation, 2D Side Views, 2D Parallel views, and 2D Perspective views (as many views as your client wishes to have) in just five minutes flat? I am sure you would.
I mean literally five minutes.
Here we go. Set the 3D view of your choice using 3dorbit or the vpoint command. Use the Flatshot command to create a new block made up of 2D objects. Select destination as Insert as new block, don’t check Show check box in Obscured lines, and click on create. The dialog box will disappear and control will move to the command line. The command sequence, similar to the block insertion sequence, will appear on the command line.
Command: flatshot
Units: Inches Conversion: 1.0000
Specify insertion point or [Basepoint/Scale/X/Y/Z/Rotate]: Select insertion point of choice
Enter X scale factor, specify opposite corner, or [Corner/XYZ] <1>: 1
Enter Y scale factor <use X scale factor>: 1
Specify rotation angle <0>: Press Enter
Oops. Your excitement dropped and you are now thinking of challenging my "five minutes" theory. The resulting block visible on your screen is not appearing as you expected. The culprit is the UCS icon. I would like to remind you that Flatshot projects a flattened view on the current XY plane. This is precisely the reason why your 2D block does not look similar to a 3D view. Before applying the Flatshot command, change UCS to UCS>View.
Command: UCS
Current ucs name: *WORLD*
Specify origin of UCS or [Face/NAmed/OBject/Previous/View/World/X/Y/Z/ZAxis] <World>: V
Now, the current XY plane is aligning with your 3D view and you are ready to take the perfect shot.
Figure 3: Flatshot of bungalow without obscured lines
Wait. I promised multiple views. What about 2D projections which can be hatched, dimensioned, and ready for other detailing? Set PLAN view after setting the UCS icon to UCS>G>Front and take the Flatshot.
Command: UCS
Current ucs name: *NO NAME*
Specify origin of UCS or [Face/NAmed/OBject/Previous/View/World/X/Y/Z/ZAxis]<World>: G
Enter an option [Top/Bottom/Front/BAck/Left/Right]<Front>: F
Command: PLAN
Enter an option [Current ucs/Ucs/World] <Current>: C
I hear chirping among novices to 3D. There is no G option shown in UCS command, but it still shows all suboptions of G. Don’t worry, be happy. Pre 2007 version users know that G stands for orthoGraphic. With the introduction of the new 3D environment in AutoCAD 2007, Autodesk opted for a visible retirement for the orthoGraphic suboption.
Figure 4: Front Elevation
Create a new layer with the user-friendly name 'FrontElevation' and Xplode the just-created block with the LA option so that exploded objects get attached with the FrontElevation layer. The Front Elevation is ready for further detailing.
Command: xplode
Select objects to XPlode
Select objects: Select flatshot block
Select objects: Press Enter 1 objects found
Enter an option
[All/Color/LAyer/LType/LWeight/Inherit from parent block/Explode] <Explode>: LA
Enter new layer name for exploded objects <0>>: FrontElevation
Object exploded onto layer FrontElevation
Similarly, you can extract a 2D plan in WCS and Left Elevation by setting UCS>G>Left.
Figure 5: Plan and Left Elevation
In my opinion, Flatshot is lagging on two fronts. Here's my unofficial wish list for the next version:
- It does not prompt for object selection; hence all solids and regions in a view are selected for producing Flatshot block.
- You can not create a Flatshot of clipped objects. It produces a flattened view of all objects in clipped mode, also.
To observe the section effect, one can either slice the model or subtract the dummy objects from the model to see a partial open model.
Figure 6: Flatshot of Sliced Model
Figure 7: Flatshot of Partially Subtracted Model
Some people with artistic inclinations still prefer to enjoy the perspective of buildings drawn as sketches. The manual color and shade effect on such sketches converts it into a nice painting worty of a drawing room. What if a perspective sketch is generated by computer in the architect’s office? Is it not a rebirth of 2D presentation again? Yes, Flatshot can create perspective, too! Are there any artists reading this? Snap as many perspective sketches as you wish through AutoCAD and play your artistic tunes of color and shades to convert it into a beautiful piece of art.
Figure 8: Perspective sketch extracted through Flatshot
If you prefer to save the extracted 2D into a different file, use the "Export to file" option while deciding the destination in the Flatshot dialog box. Don’t get distracted by the "new block" name; the flattened view saved is in 2D object primitives form and not block form. The concept is similar to a block saved as wblock. Try to export perspective view to a file and a surprise is waiting for you.
What more can you expect from Flatshotin just five minutes? If some seconds are left over, just try to move the perspective block created above and then share your surprises with your fellow AUGI members by clicking on the Discuss This button below.
(Discuss this Article! in the HotNews Discussion Forums.)
Submitted by Mohmed Zuber Shaikh. Mohmed is a civil engineer in Bharuch, employed by Sardar Sarovar Narmada Nigam Limited, Gandhinagar (India). He can be contacted via email at mzyshaikh1@yahoo.co.in
