drawing in 3d autocad 2016

Basic 3D and Surface Modelling

Introduction

Although AutoCAD has a number of commands for creating special 3D objects, a lot can be achieved by changing the properties of basic 2D objects like polylines. Most 2d objects tin be given a thickness using the thickness selection in the Properties (DDCHPROP) command. Although objects with a thickness can be said to exist extruded, this should non exist confused with the EXTRUDE command which creates solid extrusions; giving an object thickness produces a surface extrusion. All objects can be given an elevation by moving them in the Z direction using the MOVE command. With a combination of the Movement and Properties commands you lot can apace create uncomplicated 3D drawings.

Using this tutorial you volition acquire how to requite objects a thickness, how to move them vertically, how to view your 3D creations and how to apply the 3DFACE and SHADE commands.

The DDVPOINT Command

You tin use this command to get an axonometric view of your cartoon.

There are a number of ways to become an axonometric view of your AutoCAD drawing but the DDVPOINT command is probably the easiest and quickest to use. It is, however, buried ii layers deep in the pull-downwards menu so it's oftentimes quicker simply to type it at the keyboard, since at that place is no toolbar button. As you probably recognise from the control name it is a dialogue box driven command. The Viewpoint Presets dialogue box is illustrated on the right. Equally you can see, you ascertain a view by specifying two angles. The commencement angle is the rotation from the X axis (the horizontal angle). The second is the angle from the XY airplane (the vertical angle). Using the dialogue box y'all tin specify an angle either past picking on the two dials or by inbound an angle into each of the 2 bending edit boxes. Y'all can even look at your drawing from underneath by specifying a negative vertical angle. For well-nigh purposes a horizontal bending along one of the diagonals, 45, 135, 225 and 315 and a vertical angle of thirty give the best results.

You can return to a programme view of your drawing by using the PLAN control. To exercise this, just enter "Plan" at the control prompt and then to accept the "Current UCS" default. Yous can also return to whatever previous view by using the Zoom Previous control selection, Z P at the keyboard or from the Standard toolbar.

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The Backdrop Command

Y'all can apply the DDCHPROP command to change the color, layer, linetype, linetype scale and thickness of any single or multiple object selection. The DDMODIFY command gives all of these alter options in addition to those which are specific to the object type. DDMODIFY is always used past AutoCAD equally a default for unmarried object selections when the Properties command is selected from the toolbar or from the pull-downwardly menu.

Command Sequence

Control: DDCHPROP
Select objects: (pick 1 or more than objects)
Select objects:
When yous have selected the objects, the Change Properties dialogue box appears. To alter the thickness, simply enter a value (in drawing units) in the Thickness edit box. When you click the "OK" button your objects will be extruded by the amount specified.

The illustration (right) shows the result of applying a thickness to a circle. A circle with no thickness is shown on the left and a circumvolve with thickness on the right.

Effectively a circle with thickness becomes a cylinder. You can tell past the orientation of the UCS icon in this illustration that this is an axonometric view (see "The DDVPOINT Command" in a higher place for details).

Moving in the Z Direction

Past now y'all should be quite used to using the Move command merely up until now you've simply been moving 2d objects in the XY Plane. Move tin can just as easily exist used to move a drawing object vertically, perpendicular to the XY Plane. Yous tin can practise this past using XY and Z co-ordinates or by picking points in 3D space.

In the illustration on the left a circle has been moved from the base aeroplane of a cube to the top face of a cube. This is washed by using the MOVE command ( from the pull-down or from the Change toolbar). Just start the Motion command, select the circle, selection one of the lower corners of the cube as the base point (apply the end point Osnap!) and and so choice the respective top corner as the 2nd point, again using the end point Osnap. If you lot look at the circle in plan there appears to be no difference in information technology'due south position because information technology has not been moved in the XY plane but perpendicular to it. You can employ the same principle to motion any drawing entity. Comport in mind that y'all must always use an Osnap when yous are picking points in 3D infinite. If you practise not, the picked indicate will always be on the base aeroplane, which doesn't make whatsoever sense. I of the problems with this is that you may non realise your mistake until you change your view position because in the current view the objects volition appear to accept been moved commonly. It's a good idea to keep switching your view point every bit a cheque.

In the to a higher place example the move was fairly easy because nosotros had a cube to use equally a guide. Very frequently you will need to move an object vertically without whatsoever guide. In such a case you should apply co-ordinates. For example, if the cube in the illustration above was 40 drawing units high then I could move the circumvolve using the following command sequence.

Command Sequence

Command: MOVE
Select objects: (select the circle)
Select objects:
Base of operations point or displacement: 0,0,0
2d signal of deportation: 0,0,40

Observe that I employ the UCS origin point equally a base point, that's because it'south standard practice but in principle it could be whatever indicate in space. The almost important thing is that the X and Y co-ordinates remain the same (considering we exercise not want to motion in the XY Plane) and the Z co-ordinate must increment by the distance you lot want to movement up. Using co-ordinate 25,43,sixteen every bit the base point and 25,43,56 as the second signal would take resulted in exactly the same move. To movement down you lot simply need to specify a negative Z co-ordinate. For instance to move the circumvolve down past 40 units the second point co-ordinate would be 0,0,-40.

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The 3D Face up Command

The 3D Face command is used to draw 3D surfaces with 3 or 4 edges.

Control Sequence

Command: 3DFACE
Start Bespeak: (pick bespeak)
Second Point: (pick point)
Third Point: (pick point)
Fourth Point: (pick point or for just three edges)
Third Point: (start another 3D Face or to end)

Why practise I need a 3D Face up?

The reason is that when you lot requite an entity like a rectangle a thickness it is given solid sides in the direction of the extrusion only information technology is left open up ended like a tube. To add a peak and a bottom to a box yous must use 3D Faces. In the illustration on the right, ii boxes have been shaded using the Shade command, SHADE from the keyboard, from the pull-down or from the Render toolbar. Come across SHADE for a description of the Shade command options. The box on the right is a rectangle which has been given a thickness. As you tin run across, it does not have a top. A 3D Face has been added to the elevation of the box on the left which gives the upshot of a solid surface when shaded.

When you use the Shade control, don't forget to use the Regen command to get back to the wireline drawing. AutoCAD does non allow you to pick points on a shaded drawing.

For complicated shapes y'all may need to use a number of 3D Faces to fill a surface. Fortunately, extruded circles are automatically given a solid top and bottom so you don't need whatever 3D Faces. If you practise need to use a circuitous of faces to fill a surface there is a way to hibernate the join lines between faces. If you type "I" and before the first option bespeak of any border, that edge will be fabricated invisible. If you are careful you tin easily make full a complicated surface with many 3D Faces which volition only appear as a single continuous surface. If you need to create a very complex surface information technology may be improve to use the EXTRUDE control which creates solid extrusions i.e. they already have meridian and lesser surfaces.

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An Exercise

The practice beneath is designed then that you tin can practice all of the new commands and techniques outlined higher up. It is a elementary table which is composed of 9 primary elements, iv legs, 4 rails, and a meridian. These elements are all synthetic using the Rectangle control, RECTANG from the keyboard or from the pull-downwardly menu. Call back, there is nothing special about rectangles, they are just 4 sided closed polylines, so if y'all adopt using the PLINE command, then feel costless.

These rectangles will be given a thickness using the Backdrop command and an pinnacle using the MOVE command. Some 3D Faces are used for the finishing touches using the 3DFACE command.

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Drawing the Table

Step one

Commencement of all draw the table plan using the dimensions on the illustration and inset item beneath. All dimensions are in millimetres. The plan is equanimous of nine rectangles. You lot may need to utilise other commands similar Line and Beginning to construct the rectangles. Alternatively you can work out the rectangle co-ordinates and construct them manually. Remember to use the Copy and/or Mirror commands to duplicate identical objects. For example, it's actually only necessary to draw one leg since they are all the same.

Step 2

Adjacent, using the Properties command, select the 4 table legs and give them a thickness of 700. Using the Properties command a second time, select the four table rails and give them a thickness of 100. Move the track vertically through 600 with the Motility command using a co-ordinate value of 0,0,0 for the base point and 0,0,600 for the 2nd signal. Finally use the Properties command a tertiary time to requite the table elevation a thickness of 40 and use Motility again to give the top an elevation of 700. Now wait at what you accept created using the DDVPOINT command, from the pull-down or DDVPOINT at the keyboard. Use the SHADE command to run across the solid upshot, from the pull-down or SHADE at the keyboard.

Pace 3

Every bit you volition have noticed, your table does non yet take a solid pinnacle. Y'all can achieve this using 3D Face. You tin start the 3D Face command from the pull-down, , from the Render toolbar, or from the keyboard, 3DFACE. 3D Faces are defined by picking the four points of a rectangle in either a clockwise or anticlockwise direction. Start the 3D Face up command and using the endpoint Osnap, select the iv upper corners of the table top. Use the Shade command again to see the result. You tin can utilise more 3D Faces to complete the model. By looking at the tabular array from various angles y'all will notice that the underside of the track, the underside of the legs and the underside of the table top all need 3D Faces in lodge to create a completely solid model.

Now that you have completed your model, experiment with the Shade command and the various shade edge settings (see "Tips and Tricks" below).

Step four

To end your cartoon, set tilemode to 0, create an A3 drawing sheet and insert some tiled viewports, meet thePaper Infinite exercise for details. Your drawing should cease up looking something similar the one below. The vase was created using the REVSURF control, come across REVSURF for details.

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3D Objects

In addition to the simple 3D objects you can create by giving objects thickness and adding 3D Faces, AutoCAD provides a number of ready fabricated 3D objects. These objects can exist chosen from the 3D Objects dialogue box. As you can see from the illustration of the dialogue box below, yous can create very simple objects like a box and complex ones similar the torus.

You must invoke the 3D objects dialogue box from the pull-downwards card, as there is no keyboard equivalent. Alternatively yous can select individual 3D Object commands from the Surfaces toolbar. Each 3D Object requires different input from the user but the command line is quite explicit then you shouldn't have whatever issues.

1 of the nigh useful objects is the Sphere. In the illustration on the right a 3D tree has been created using a circle with thickness as the trunk and a sphere as the canopy. One thing to bear in mind when creating spheres is that the heart of the sphere will be on the basis plane. Therefore, one-half of the sphere is below ground level and one-half above. If yous desire the sphere to sit on the ground plane, all you have to do is move it up through a distance which is the same as it'south radius.

Another consideration when creating spheres and some of the other shapes is the number of segments to utilise. It is very tempting to use a lot and create a smooth shape but this does have lots of drawing memory and so become carefully. The default value (16) is commonly adequate for most purposes.

Control Sequence

Invoke the dialogue box from the pull-down (), pick the sphere icon and and then the "OK" button or choice from the Surfaces toolbar.

Eye of sphere: (selection point)
Diameter/<radius>: (pick betoken or enter value)
Number of longitudinal segments<16>: (enter number or)
Number of latitudinal segments<16>: (enter number or)
Your Sphere is drawn.

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Tips & Tricks

• If y'all would like to try creating the vase every bit shown in the table drawing. Yous volition need to know a little scrap about UCS, User Co-ordinate Systems (see UCS) and how the Revolved Surface command works (see the 3D Tree exercise for details).
• You tin can change the shaded effect that the Shade command gives to your drawing using the SHADEDGE variable. To change the shade border variable only enter SHADEDGE at the keyboard and enter a value between 0 and 3.
  SHADEDGE = 0 gives a shaded color surface with no lines.
  SHADEDGE = one gives a shaded colour surface with lines. This tends to give the best overall results.
  SHADEDGE = 2 gives a background colour surface which gives a similar upshot to the Hibernate control.
  SHADEDGE = 3 gives a block colour surface, this is the AutoCAD default. Run into SHADE for a fuller description of the SHADEDGE variable.
• Always utilize Osnaps when picking in 3D.
• Employ the Shade command regularly to keep track of your drawing. In wireline it'south impossible to tell if a surface has a 3D Face or not, and then you'll need to employ Shade to check.
• Y'all can force invisible 3D Face edges to display in wireline using the SPLFRAME variable. If SPLFRAME = 0 all invisible edges remain hidden. If information technology is set to 1 invisible edges will be displayed. This tin can be extremely useful because information technology is incommunicable to select a 3D Face up which has no visible edges. The only way to select such a 3D Face is to ready SPLFRAME to 1 first.

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