Transitioning from 2D to 3D AutoCAD drawings 115

Thanks To Auto cad Insider-Heidi

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.

1. 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.
2. Select the small box, right-click and choose Move.
3. Pick the midpoint of the back vertical side of the box.
   
   
4. Pass the cursor over the midpoint of the vertical side of the VAV box.
5. Move the cursor towards the intersection of the horizontal and vertical tracking vectors and pick.
   
   
6. Erase the 2D geometry.
7. 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 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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Transitioning from 2D to 3D AutoCAD drawings 109

Okay… so you don’t want your light fixtures on the floor?!?

There are many methods that enable you to change the position of objects in 3D space. Most of them are the same methods you use to change the position of objects in 2D! But, if you are new to working in a 3D environment, you might need to think a little more about which option to choose. For example, how should I select the orange light fixtures that I want to move? I could pick them one at a time but that sounds like a lot of work.

I could change to a plan view and then use several window/crossing selections just as I might do in 2D.

I could change to a front or side view and then use a window selection to choose just those objects (the light fixtures) that are at the floor level.

Or, the method that I’m going to use is the Properties window. Since all the objects that I want to select are blocks and because the light fixtures are the only visible blocks, I can select all the objects on my screen and then use the Properties window to select only the object type (Block references) that I want. This capability has been around since AutoCAD 2000 (if my memory servers) and it can be very useful whether you are working in 3D or 2D.

So why did I choose to use the Properties window for selection? Because, I can also use the Properties window to “move” my light fixtures to a new height. Rather than using the MOVE or 3DMOVE commands, I can simply change the Z position of all the blocks to the proper value.

1. Select all the objects.
2. Right-click and choose Properties from the menu.
3. In the Properties window, select Block Reference from the drop-down list.
4. For the Z Position, enter the proper value. In my drawing, the bottoms of the light fixtures were originally inserted at a Z Position of 0 but I want them to be located at ceiling height which is 8’.
   
   

This method was the quickest in my situation because 1) it was easy for me to select all the right blocks and 2) I knew at what height (Z Position) the blocks should be. If I didn’t know the exact Z Position for the blocks, I would probably use a different selection method and then use the new 3DMOVE grip tool to move the blocks along the Z-axis at a relative distance (8').

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Transitioning from 2D to 3D AutoCAD drawings 108

In this series, I previously converted the structural elements and the walls from 2D to 3D objects. I turned off the structural elements (columns and beams) and turned on the lighting layer so that I can convert the 2D lighting fixtures to 3D.

Fortunately, my original 2D drawing included a reflected ceiling plan that used blocks to represent the various light fixtures. I can use what I already know about block editing to update the block definitions to 3D. As I mentioned in a previous post, I can use various methods for editing the block definition; however, I suggest using the REFEDIT command. Once I’m in the reference edit mode, I can use any of my 3D tools to create the 3D model. I can use the PRESSPULL or EXTRUDE functionality that I described in previous posts or I can use primitive objects (BOX, SPHERE, CYLINDER, etc). I prefer to use primitive objects, when possible, because they have the most editing flexibility.

1. Zoom into a light fixture.
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 Box.
   
5. With the endpoint object snap on, pick opposite corners of the existing rectangle.
6. Drag the cursor up and pick a point or enter a value for the height. Even if you don't know the exact height, you can specify some value and then easily edit it later using grips or the properties palette. Keep in mind, however, that you must first access the block definition just as you would when editing 2D block geometry.
   
   
7. On the Refedit toolbar, choose Save Reference Edits. All of the block references for that particular type of light fixture 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 procedure for the other light fixtures. Notice, however, that the light fixtures are on the floor. In a future post, I’ll show you one (of many) methods that will enable you to move them to the proper height.

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