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ALIGN vs 3DALIGN

In my last post, I described the ALIGN command and how you can use it to move and rotate objects in 3D space. In this post I’ll compare it with the 3DALIGN command (3AL command alias).
The purpose of ALIGN and 3DALIGN is the same but the procedure differs. When you use the ALIGN command, you pick 3 sets of 2 points (source 1, destination 1; source 2, destination 2; source 3, destination 3). When you use the 3DALIGN command, you pick all the source points first and then pick the destination points. The following image illustrates the difference in pick points resulting in the same transformation.

The 3DALIGN command provides the added benefit of enabling you to copy the objects as you align them.  Simply choose the Copy option before picking the source points. The selected object remains in its original location while a copy is automatically aligned according to your pick points.

The 3D Move Gizmo

If you work in 3D or if you don’t work in 3D but are thinking about it, you’ll definitely want to learn about the AutoCAD 3D “Gizmos”. The gizmos, also known as grip tools, were introduced in AutoCAD 2007 and provide an efficient and intuitive way for you to edit objects in 3D space.
The Move gizmo enables you to restrict the movement of selected objects or sub-objects to a specified axis or plane. You can activate the Move gizmo using any of the following methods:

• Enter the 3DMOVE command at the Command Line and then select the object(s) or sub-object(s) you want to move.
• Set the 3D Modeling workspace and choose the 3D Move button from the Modify panel of the Home ribbon tab and then select the object(s) or sub-object(s) you want to move.
  
• Set the current visual style to any 3D visual style and then select an object or sub-object.
  

When the Move gizmo is activated, it displays the X,Y, and Z axes as thick red, green, and blue vectors. Between each set of axes, is a square representing the plane defined by those axes.

If you pass the cursor over one of the vectors, the vector turns yellow and a continuous line is displayed in the original color indicating the axis of constraint. To constrain movement along the axis, click on the yellow vector.

With the selected object(s) constrained to an axis, you can drag the cursor and enter a displacement value or snap to key points on existing objects.

Only the coordinate value (X, Y, or Z) corresponding to the constrained axis will change.

AutoCAD 3D Online Course

If you are interested in learning about the 3D modeling tools in AutoCAD 2007 and 2008, you can view the Transitioning to 3D with Ease in AutoCAD® 2007 course that I taught at Autodesk University 2006. You'll have to register with AU Online and then log in using your name and password. After you log in, you'll see a link to "View the Screencast" on the right side of the page.

 

If you are creating 3D objects in an older version of AutoCAD, it's well worth you time to check out this newer functionality!

Transitioning from 2D to 3D AutoCAD drawings 116

During this series of posts, I’ve demonstrated many of the AutoCAD 2007 tools and tricks that enable you to transition from 2D drawings to the exciting world of 3D. In these examples, I’ve used a building systems drawing but keep in mind that you can apply all of these tools and tricks to any industry and they are particularly useful for conceptual design. As you become comfortable in the world of 3D and want to get serious about creating 3D models, you should consider Autodesk’s industry-specific 3D modeling applications. Since many of Autodesk’s industry applications use AutoCAD as a foundation, the tools and tricks you learn when transitioning from 2D to 3D AutoCAD will directly apply to these more powerful applications. For example, Autodesk Building Systems enables you to combine the core AutoCAD tools that I’ve shown with automated tools and libraries specifically designed for building systems. You can create 3D building systems models in significantly less time and with more flexibility.

For more information about Autodesk’s industry-specific applications, visit www.autodesk.com and select the appropriate industry.

Transitioning from 2D to 3D AutoCAD drawings 115

Continuing with my “Transitioning from 2D to 3D AutoCAD Drawings” series, I want to copy the current duct to multiple locations and then edit the length and diameter accordingly. Of course, I could draw a new cylinder, repeating the process from my previous post. Or, I could create the ductwork using other methods such as extruding a circle along a path. However, I think copying and editing the cylinders is the most efficient. In older versions of AutoCAD (prior to AutoCAD 2006), editing existing objects was much more difficult and I wouldn’t have even considered this method.

1. Select the cylinder
2. Right-click and choose Copy Selection.
3. Pick the Center of the end of the column to specify the base point.
   
4. Pick the midpoints of each of the ends of the 2D ducts.
   
5. Select a cylinder and then select the length grip.
6. Select the midpoint of the end of the intersecting duct to ensure the cylinder stretches to the middle of the duct.
   
7. Continue editing the existing cylinders by stretching the length or diameter as necessary.
   
   
   You can easily create all the ducts that have the same orientation by repeating this process of copy/grip-edit.
   

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Transitioning from 2D to 3D AutoCAD drawings 114

In my last “Transitioning from 2D to 3D” post, I finished creating the 3D VAV boxes in the HVAC plan. The VAV boxes are currently on the floor. I could move them to the ceiling now, but I decided to wait until I finish creating the ductwork so that I can move the ducts and VAV boxes at the same time.

The ductwork provides the opportunity to use a variety of AutoCAD tools. As usual, there are many different ways to create the same model. I’m going to focus on the methods that enable you to take advantage of the existing 2D geometry using the fewest steps and/or the least amount of thinking.

1. Zoom into an area with ductwork.
   
2. From the Dashboard, choose Cylinder.
3. Pick the midpoint and endpoint of the existing 2D duct to specify the radius of the cylinder. Don’t worry that the cylinder is oriented incorrectly.
4. Drag down a small distance and pick to set the height of the cylinder. You could just as easily drag up. We’ll rotate the cylinder into the proper position and then adjust its height by snapping to existing 2D geometry.
   
5. Select the cylinder and then pass your cursor over the Move grip at the cylinder base. The Move grip tool will display.
6. Select the axis around which you want to rotate. By default, AutoCAD will try to move the selected object along the axis but you can easily switch to Rotate functionality.
   
7. Press the spacebar twice to change from the Move grip tool to the Rotate grip tool.
8. Drag the cursor straight up (along the z polar axis) and pick or enter an angle of 90. If you drew the initial cylinder (step 4) up instead of down, you would do the opposite for this step.
   
9. Select the stretch grip at the end of the cylinder and stretch it to the proper height. The “proper height” depends on what your goal is for the model. If you want the model to be as close to real life as possible, you might want to create each duct segment, including the connectors, as separate objects. However, if you are only concerned with how the model looks, you can reduce steps by combining several “parts” into one. I decided to stretch the duct all the way to center of the large duct to which it will connect. It doesn’t exactly match the real-world parts, but it is quick and will “look” fine after I create the larger duct.
10. Pick the midpoint of the line at the end of the large duct.
    
    I could have “eye-balled” a distance that would extend the small cylinder far enough into the larger cylinder, but if I didn’t stretch far enough, there would be a gap at the intersection of the two cylinders. If I stretched too far, the small duct might protrude to the other side of the large one. By stretching to the middle of the larger duct, I know there won’t be any gaps or excess protrusions.

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Transitioning from 2D to 3D AutoCAD drawings 113

Continuing work on the VAV box from my previous post, I’ll create the extrusions for the primary air inlet and the supply outlet. Since the VAV box is a block, I used REFEDIT to modify the block definition. I’ll continue with my edits from within the REFEDIT command.

1. Press Shift and the middle mouse button to orbit around to the opposite side of the model.
   
2. From the Dashboard, choose Cylinder to draw the protrusion representing the primary air inlet.
3. Pass the cursor over the side of the box to activate it as the current work plane (the DUCS toggle must be on).
4. Pass the cursor over the midpoint of the back line representing the 2D air inlet to acquire the point (midpoint OSNAP and OTRACK must be on).
5. Pass the cursor over the midpoint of the vertical edge of the VAV box.
6. Move the cursor towards the intersection of the two tracking vectors and pick. I could have drawn the cylinder at the midpoint of the 2D geometry and then moved it up like I did in the last post… but this alternate method saves a few steps.
   
7. Pass the cursor over the endpoint of the back line representing the 2D air inlet to acquire the point. I could enter a value for the radius of the cylinder but since I have appropriate 2D geometry, I might as well use my object snaps and tracking.
8. Move the cursor towards the intersection of the horizontal and vertical tracking vectors and pick.
   
9. Drag the cursor out and pick a point (ie. midpoint, endpoint) on the front line of the 2D air inlet. I could enter a value for the height of the cylinder but I wouldn’t want to think that hard! I might as well use the existing 2D geometry!
   
10. From the Dashboard, choose Box to draw the protrusion representing the supply outlet. Instead, I could use the Ctrl-Alt (Presspull) functionality similar to the previous post. This is just another option.
11. Pick opposite endpoints of the existing 2D rectangle.



12. Enter the height of the box. I entered a height of 14. The box representing the supply outlet needs to be vertically centered on the VAV box. I’ll use the MOVE command to move it into position.
13. Select the small box, right-click and choose Move.
14. Pick the midpoint of the back vertical side of the box.
    
15. Pass the cursor over the midpoint of the vertical side of the VAV box.
16. Move the cursor towards the intersection of the horizontal and vertical tracking vectors and pick.
    
17. Erase the 2D geometry.
18. On the Refedit toolbar, choose Save Reference Edits.
    

If you have other versions of similar block definitions, you can repeat these steps to update all of them.

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Transitioning from 2D to 3D AutoCAD drawings 112

In my previous posts, I updated my 2D plan to include 3D objects for the columns and beams, walls, lights and diffusers. To get a better idea of how this drawing looks, I’ll set the conceptual visual style.

The next thing I want to update is the VAV box in the HVAC plan. To make it easier to see the 2D objects that I’m working with, I’ll turn off all the layers except for the 2D walls and HVAC plan. The HVAC plan uses blocks for the 2D VAV box. I’ll edit these block definitions using the REFEDIT tool similar to how I edited the column, beam, lighting, and diffuser blocks. Although the process I’ll use is not drastically different, this block has a few more components, giving me the opportunity to explore different methods.

1. Zoom into a VAV block.
2. Select one of the block references, right-click and choose Edit Block In-place. This launches the REFEDIT command.
3. In the Reference Edit dialog box, choose OK.
4. Press the Ctrl and Alt keys and pick inside the VAV box.
5. Drag the cursor up and pick a point or enter a value for the height. I entered a height of 17.125.
   
6. Press the Ctrl and Alt keys and pick inside the small rectangle representing the induced air outlet.
   
7. Drag the cursor up and pick a point or enter a value for the height. I entered a height of 14. The small box representing the induced air outlet needs to be vertically centered on the large box. You can use various tools to move it, including the MOVE command.
8. Select the small box, right-click and choose Move.
9. Pick the midpoint of the back vertical side of the small box.
   
10. Drag the cursor over the back endpoint of the 2D rectangle representing the small box and the midpoint of the vertical side of the large box to acquire these points. You don’t want to pick the points, you only want to pass over them so you can use Otracking (OTRACK must be enabled on the status bar). If you are not familiar with Otrack, these few steps are probably confusing… sorry…  This is easier to show than to explain. Viewing the animation will probably be very helpful for these particular steps.
11. Drag the cursor to the approximate location where you want to move the small box. You’ll know if AutoCAD acquired the points because the tracking vectors will display and the tool tip will indicate that it is tracking the Z values of the Endpoint and the Midpoint.
    

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Using these familiar tools (Osnaps. Otrack, MOVE, etc) you can easily manipulate objects in 3D space. We still need to make more changes to the VAV box. In the next posting, I’ll create the last two protrusions using slightly different methods.

Transitioning from 2D to 3D AutoCAD drawings 111

When I left off last week, I had 3D diffusers on the floor. Did you think about how I might move them to the ceiling?

As I mentioned in a previous post, there are many methods for selecting and moving the geometry in 3D space. I decided to use the Quick Select tool to select the objects and the standard MOVE command (rather than the 3DMOVE) to move the selected objects along the Z-axis.

1. In the drawing, right-click and choose Quick Select from the right-click menu.
   
2. In the Quick Select dialog box, set the Object Type to the type of object you want to move. Since I want to move blocks, I’ll set the Object Type to Block Reference.
3. Set the type of property for which you want to filter the selection. The property you choose depends on the drawing. In my example, I could filter on the block name. However, I have several different diffuser blocks so I would have to perform multiple sets of filters in order to select all of them. All of the diffuser blocks are on the same layer and they are the only blocks on that layer. So, in my example, the easiest method for selecting all the diffuser blocks is to filter on the layer.
4. Ensure the Operator is set to Equals.
5. Set the Value to the proper layer name. In my example, I set it to the M-HVAC-CDFF; the layer on which all my diffusers are inserted.
    
6. Choose OK. All block objects on the specified layer are selected and ready to be moved.
7. Right-click and choose Move.
8. Specify the basepoint by picking in a blank area in 3D space. This is no different than how you might move objects in a 2D drawing.
9. Ensure that polar tracking is enabled (POLAR toggle on the status bar). If polar tracking is enabled, you will see the Z tracking vector when you drag the cursor in the direction of the Z-axis.
10. Drag the cursor up along the Z-axis and enter the displacement distance. The displacement distance is 8’ in my example.
    

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Transitioning from 2D to 3D AutoCAD drawings 110

Now that we have lights… on the ceiling… let’s take a look at the diffusers. The diffusers are block insertions so I can update them quickly using the Refedit command, similar to how I updated the lighting fixture blocks.

The shape of the diffusers is a little more complex than the box-shaped lighting fixtures. That’s good! It gives me a chance to show you some other primitive tools!

The 2D block of the diffuser is flat and square. But, the real-life diffuser is a pyramid shape so I’m going to use the new Pyramid command in AutoCAD 2007. If you remember when I drew the box for the lighting fixture, it was like drawing a rectangle with height. Similarly, drawing a pyramid is like drawing a polygon with height. The first few prompts and options are just like the POLYGON command. To make the diffuser even more interesting and realistic, I’ll add a cylinder to the top face to represent the neck.

1. Zoom into a diffuser.
2. Select one of the block references, right-click and choose Edit Block In-place. This launches the REFEDIT command.
3. In the Reference Edit dialog box, choose OK.
4. From the Dashboard, select Pyramid.
   
5. Right-click and choose Sides.
6. Enter the number of sides for the pyramid. For this diffuser, I will enter 4.
7. Right-click and choose Edge. In this example, I could just as easily use the default Center option but I figured this way it is more obvious how the Pyramid options match the Polygon options.
8. With the endpoint object snap on, pick two endpoints on an edge of the existing 2D diffuser block. Now that I’ve defined the 2D shape (like a polygon), I am prompted for the 3D information.
   
9. Drag the cursor up and pick a point or enter a value for the height. I’ll enter a height of 1.25. The Pyramid is complete after entering the height. However, it used a default top-radius of zero, creating a point at the top. Before I entered the height, I could have right-clicked and selected the Top Radius option to make it flat on top. However, even after I create the Pyramid, I can edit its properties.
10. Select the Pyramid. I could enter a value for the top radius but I don't know what that value should be. Yes, I could figure it out using the DISTANCE command and snapping to the existing 2D geometry but I don’t want to work that hard! Instead, I’m going to use the Pyramid’s grips to snap to the existing geometry.
    
11. Select the grip for the top radius and stretch it out to the midpoint of the 2D geometry. In addition to grip-editing, you can use the Properties palette to modify the properties of a pyramid. You could, for example, change the number of sides, height, base radius, or top radius.
12. From the Dashboard, select Cylinder. Now I'm ready to create the neck of the diffuser.
13. Pass the cursor over the top face of the pyramid. The face should highlight indicating that it is the active workplane.
14. With the face highlighted, pass the cursor over the midpoints of two adjacent edges of the face. This will enable you to acquire the midpoints without actually picking. You must ensure that Osnap (with midpoint) and Otrack are toggled on. When AutoCAD acquires the points you will see yellow blips at the midpoints.
    
15. Pass the cursor toward the center of the face, until the tracking vectors is displayed indicating that it found the midpoint object snaps, and then pick. If these last few steps seem new, confusing, and overwhelming, they shouldn’t! This valuable 2D functionality has been around since AutoCAD 2000 and once you get familiar with how to use it, you’ll wonder how you worked without it.
    
16. Drag the cursor out and pick a point or enter a value for the radius of the cylinder. I want a radius of 3.
17. Drag the cursor up and pick a point or enter a value for the height of the cylinder. I’ll enter 1. But, again, I can change these values using grips or the Properties window.
18. Erase the 2D geometry to clean up the block.
    
19. On the Refedit toolbar, choose Save Reference Edits.  All of the block references for that particular type of diffuser will update with the new 3D geometry just as you would expect them to do when you make 2D edits to the block definition. I can repeat this process for similar block definitions of other diffusers.

Yeah!! We have diffusers! On the floor!

Think about how you might move the diffusers to the ceiling… or wait for a future post :-)

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