Modelling with AutoCAD 2004 phần 5 docx

3 With layer EDGE current, create the following touching edges similar in layout to Fig. 19.1(a): a) four lines b) four three point arcs c) four single 90 degree polyline arcs (use CE option) 4 Set SURFTAB1 to 10 and SURFTAB2 to 7 (command line entry) 5 Select the EDGE SURFACE icon from the Surfaces toolbar and: prompt Select object 1 for surface edge respond pick a point on any line prompt Select object 2 for surface edge respond pick a point on another line prompt Select object 3 for surface edge respond pick a point on a third line prompt Select object 4 for surface edge respond pick a point on the fourth line 6A 10ϫ 7 surface mesh is stretched between the four touching lines as Fig. 19.1(a1) 7 a) Erase the added edge surface b) Set SURFTAB1 and SURFTAB2 to 18 c) Menu bar with Draw-Surfaces-Edge Surface and pick the four touching lines in any order d) The edge surface mesh is displayed as Fig. 19.1(a2) 8 At the command line enter EDGESURF ϽRϾ and pick the four arcs to display the edge surface mesh as Fig. 19.1(b) 9 Set both SURFTAB1 and SURFTAB2 to 10 and add an edge surface mesh between the four touching polyarcs – Fig. 19.1(c). The result of this mesh is quite interesting? This completes the first exercise and it need not be saved. Example 2 (a 3D edge surface mesh) 1 Open your MV3DSTD template file (MVLAY1 tab) 2 Refer to Fig. 19.2 3 With layer MODEL, UCS BASE and the lower left viewport active, use the LINE icon to draw the four touching lines: Start point: 0,0,0 Next point: 150,0,Ϫ20 Next point: 180,200,30 Next point: 40,120,50 Next point: close 4 The four lines will be displayed as Fig. 19.2(a) 5 Centre each viewport about the point 90,100,25 at 250 magnification 6 Make a new layer, MESH colour blue and current 7 Set both SURFTAB1 and SURFTAB2 to 10 8 Using the edge surface icon, pick the four lines in the order indicated 1–2–3–4 as Fig. 19.2(a) 130 Modelling with AutoCAD 2004 9 An edge surface mesh will be stretched between the four lines as Fig. 19.2(b) 10 In paper space, zoom the 3D viewport and return to model space 11 Menu bar with Modify-Object-Polyline and: prompt Select polyline respond pick any point on mesh prompt Enter an option [Edit vertex/Smooth surface/ enter E ϽRϾ – the edit vertex option prompt Current vertex (0,0) then Enter an option [Next/Previous/ and an X is displayed at the 0,0 vertex – leftmost? enter U ϽRϾ until X is at vertex (10,0) and: prompt Current vertex (10,0) then Enter an option [Next/Previous/ enter M ϽRϾ – the move option prompt Specify new location for marked vertex enter @0,0,60 ϽRϾ and DO NOT EXIT COMMAND 12 We now want to alter other vertices of the mesh to create a raised effect. This will be achieved by: a) moving the X to the required vertices b) using the M option c) entering the required relative vertex co-ordinates Edge surface 131 Figure 19.2 Edge surface Example 2 – 3D with edit vertices. 13 Use the N/D/L/R/U options and enter the following new locations for the named vertices: relative movement vertices @0,0,50 9,0 10,1 @0,0,40 8,0 9,1 10,2 @0,0,30 7,0 8,1 9,2 10,3 @0,0,20 6,0 7,1 8,2 9,3 10,4 @0,0,10 5,0 6,1 7,2 8,3 9,4 10,5 14 When all the new vertex locations have been entered: a) enter X ϽRϾ to exit the edit vertex option b) then enter X ϽRϾ to end the command 15 The mesh will be displayed with a ‘raised corner’ as Fig. 19.2(c) 16 At the command line enter PEDIT ϽRϾ then: a) pick any point on the mesh b) enter E ϽRϾ for the edit vertex option c) use the N/U/R/L/D entries to move the X to the following named vertices and with the M (move option), enter the following new locations: relative movement vertices @0,0,Ϫ80 4,10 @0,0,Ϫ50 3,10 4,9 5,10 @0,0,Ϫ30 2,10 3,9 4,8 5,9 6,10 @0,0,Ϫ10 1,10 2,9 3,8 4,7 5,8 6,9 7,10 d) exit the vertex option with X ϽRϾ e) exit the polyline edit command with X ϽRϾ 17 These vertex modifications have produced a v-type notch in the mesh as Fig. 19.2(d) 18 Paper space and zoom previous then model space. Freeze the MODEL layer 19 The complete four viewport configuration of the edge surface mesh is displayed in Fig. 19.2(e) 20 The exercise is now complete – save if required 21 Now investigate the effect of the smooth surface option (S) on the mesh. Example 3 (an edge surface mesh created from splines) This example will demonstrate how an edge surface can be stretched between four spline curves to simulate a car body panel. 1 Open your MV3DSTD template file as usual, i.e. MVLAY1 tab, layer MODEL and UCS BASE 2 In all viewports, zoom-extents then zoom to a factor of 1.75, but 1.5 in the 3D viewport 3 With the lower left viewport active, refer to Fig. 19.3 and by selecting the SPLINE icon from the Draw toolbar, draw four spline curves using the following co-ordinate information: spline 1 spline 2 spline 3 spline 4 first point 0,0,0 Ϫ200,0,0 Ϫ200,120,120 0,0,0 next point Ϫ200,0,0 Ϫ200,0,100 0,100,90 0,0,75 next point ϽRETURNϾϪ200,120,120 ϽRETURNϾ 0,100,90 next point – ϽRETURNϾ – ϽRETURNϾ start tan 0,0,0 Ϫ200,0,0 Ϫ200,120,120 0,0,0 end tan Ϫ200,0,0 Ϫ200,120,120 0,100,90 0,100,90 132 Modelling with AutoCAD 2004 4 The four spline curves will be displayed as Fig. 19.3(a) 5 Make a new layer, MESH colour blue and current 6 Set both SURFTAB1 and SURFTAB2 to 18 7 Using the Edge Surface icon, pick the four spline curves and the result should be similar to Fig. 19.3(b) 8 Task a) Use the View-Hide sequence in the four viewports, and you will probably not notice any difference b) Gouraud shade the four viewports and the effect is impressive c) Use the 3D orbit command in the 3D viewport, and real-time rotate the shaded model. This is really impressive. 9 Save if required, as this completes the edge surface exercises. Summary 1 An edge surface is a polygon mesh stretched between four touching objects – lines, arcs, splines or polylines 2 An edge surface mesh can be edited with the polyline edit command 3 The added surface is a COONS patch and is bicubic, i.e. one curve is defined in the mesh M direction and the other is defined in the mesh N direction 4 The first curve (edge) selected determines the mesh M direction and the adjoining curves define the mesh N direction Edge surface 133 Figure 19.3 Edge surface Example 3 – using splines. 5 The mesh density is controlled by the system variables: a) SURFTAB1: in the mesh M direction b) SURFTAB2: in the mesh N direction 6 The default value for SURFTAB1 and SURFTAB2 is 6 7 The type of mesh stretched between the four curves is controlled by the SURFTYPE system variable and: a) SURFTYPE 5 – Quadratic B-spline b) SURFTYPE 6 – Cubic B-spline (default) c) SURFTYPE 8 – Bezier curve 8 The SURFTYPE variable controls the appearance of all mesh curves. Assignment Activity 12: The flat-topped hill made by MACFARAMUS. MACFARAMUS was contracted by the emperor TOOTENCADUM to create a flat- topped hill for a future project. The activity is very similar to the second example, i.e. an edge surface has to have sev- eral of its vertices modified to give a ‘flat-top hill’ effect. The process is quite tedious, but persevere with it as it is needed for another activity in a later chapter. 1 Use your MV3DSTD template file with UCS BASE as usual 2 Zoom-centre about 0,0,50 at 400 magnification originally 3 With layer MODEL, create four touching polyline arcs of radius 200 with 0,0 as the arc centre point. If you are unsure of this, use the Centre, Start, End ARC option. 4 Make a new layer called HILL, colour green and current 5 Set SURFTAB1 and SURFTAB2 to 20 6 Add an edge surface to the four touching arcs 7 I suggest that, for editing the vertices of the edge surface, you work with the model tab active at a SE Isometric viewpoint 8 Use the Modify-Object-Polyline (PEDIT) command with the Edit Vertex option to move the following vertices by @0,0,100: a) 6,9 6,10 6,11 b) 7,7 7,8 7,9 7,10 7,11 7,12 7,13 c) 8,7 8,8 8,9 8,10 8,11 8,12 8,13 d) 9,6 9,7 9,8 9,9 9,10 9,11 9,12 9,13 9,14 e) 10,6 10,7 10,8 10,9 10,10 10,11 10,12 10,13 10,14 f) 11,6 11,7 11,8 11,9 11,10 11,11 11,12 11,13 11,14 g) 12,7 12,8 12,9 12,10 12,11 12,12 12,13 h) 13,7 13,8 13,9 13,10 13,11 13,12 13,13 i) 14,9 14,10 14,11 9 Note: a) The named vertices all lie within a circle of radius 100 b) Use the N/U/D/L/R entries of the edit vertex option until the named vertex is displayed then use the M option with an entry of @0,0,100 10 When all the vertices have been modified, optimise the multiple viewport viewpoints. I used four different VPOINT-ROTATE values and the effect with hide was quite ‘pleasing’ 134 Modelling with AutoCAD 2004 11 Save this drawing as MODR2004\HILL as it will be used with a later activity 12 The View-Shade-Gouraud Shaded effect then 3D orbit with the model tab active is very interesting. You can rotate the model to ‘see inside’ the raised part of the edge surface. 13 Additional exercise Can you edit vertices to produce a step effect as displayed in actual activity drawing. No help with this, but you have the ability to complete this. Edge surface 135 A 3D polyline is a continuous object created in 3D space. It is similar to a 2D polyline, but does not posses the 2D versatility, i.e. there are no variable width or arc options available with a 3D polyline. It does have limited editing options, but the real benefit of a 3D polyline is that it allows x,y,z co-ordinates to be used. A 2D polyline can only be created in the plane of the current UCS. Example This exercise will create a series of hill contours from splined 3D polylines, so: 1 Open your MV3DSTD template file, MVLAY1 tab with the lower left viewport active and UCS BASE 2 Refer to Fig. 20.1 and make the following new layers: LEVEL1, LEVEL2, LEVEL3, LEVEL4 – all colour green PATHUP: red; PATHDOWN: blue DOWNN: magenta Chapter 20 3D polyline Figure 20.1 3D polyline example. 3D polyline 137 3 With layer LEVEL1 current, menu bar with Draw-3D polyline and: prompt Specify start point of polyline and enter: 0,50,0 ϽRϾ prompt Specify endpoint of line and enter: 50,0,0 ϽRϾ prompt Specify endpoint of line and enter: 150,0,0 ϽRϾ prompt Specify endpoint of line and enter: 220,60,0 ϽRϾ prompt Specify endpoint of line and enter: 260,140,0 ϽRϾ prompt Specify endpoint of line and enter: 170,180,0 ϽRϾ prompt Specify endpoint of line and enter: 20,160,0 ϽRϾ prompt Specify endpoint of line and enter: c ϽRϾ 4 Make layer LEVEL2 current and at the command line enter 3DPOLY ϽRϾ and: prompt Specify start point of polyline and enter: 40,60,50 ϽRϾ prompt Specify endpoint of line and enter: 80,20,50 ϽRϾ prompt Specify endpoint of line and enter: 140,35,50 ϽRϾ prompt Specify endpoint of line and enter: 200,100,50 ϽRϾ prompt Specify endpoint of line and enter: 130,140,50 ϽRϾ prompt Specify endpoint of line and enter: 60,130,50 ϽRϾ prompt Specify endpoint of line and enter: c ϽRϾ 5 With layers LEVEL3 and LEVEL4 current, use the 3D polyline command with the fol- lowing co-ordinate values: Level3 Level4 Start point: 70,70,100 85,70,125 Endpoint: 80,35,100 90,50,125 Endpoint: 130,45,100 130,60,125 Endpoint: 170,90,100 130,80,125 Endpoint: 100,120,100 close Endpoint: close 6 Menu bar with Modify-Object-Polyline and: prompt Select polyline respond pick the 3D polyline created at level 1 prompt Enter an option enter S ϽRϾ – the Spline option prompt Enter an option enter X ϽRϾ – the exit command option 7 The selected polyline will be displayed as a splined curve 8 Use the S option of the Edit Polyline command to spline the other three 3D polylines 9 Zoom-centre about 120,90,60 at 200 magnification in all viewports 10 With layer PATHUP current, use the 3D polyline command with the following entries: Start: 0,50,0 –level 1 point Endpoint: 60,130,50 –level 2 point Endpoint: 100,120,100 –level 3 point Endpoint: 130,60,125 –level 4 point Endpoint: ϽRϾ 11 This 3D polyline is a path ‘up the hill’ and each entered co-ordinate value is a point on the level 1,2,3,4 contours 12 Spline this polyline, and it does not pass through the entered co-ordinates 13 Task 1 a) Using the ID command, identify the co-ordinates of the points A, B and C where PATHUP ‘crosses’ the level 2, 3 and 4 contours. My values were, with UCS BASE current: ptA: 55.06, 101.57, 50 ptB: 95.42, 101.91, 100 ptC: 127.07, 65.65, 125 b) With layer PATHDOWN current, create a 3D polyline as a ‘path down the hill’, this path to be drawn as a vertical line in the top (lower right) viewport. It has to ‘touch’ each contour, and if possible, be the shortest distance (ortho on helps, as does OSNAP nearest). Do not spline this path. Find the distance from top to bottom for this path. c) My value was 136.38 (remember that there are three segments) 14 Task 2 MACFARAMUS erected a pole at the top of this contoured hill, probably as a signalling device. The pole was 25 units tall and its base co-ordinates were 110,65,125. From the base of this pole, a path down the hill in a northward direction was carved out of the hill. The north direction is given in Fig. 20.1. Using this information: a) with the DOWNN layer current, create this northward 3D polyline path down the hill, the path to just touch a contour b) find the distance from the base of the pole to the base of this new northward path c) My linear distance for the four segments of the northward path down the hill was 198.89 15 The exercise is now complete. Save if required. Summary 1 A 3D polyline is a single object and can be used with x,y,z co-ordinate entry 2 A 3D polyline can be edited with options of Edit vertex, Spline and decurve 3 3D polylines cannot be displayed with varying width or with arc segments 4 The command is activated from the menu bar or by command line entry. 138 Modelling with AutoCAD 2004 AutoCAD has nine pre-defined 3D objects, these being box, pyramid, wedge, dome, sphere, cone (and cylinder), torus, dish and mesh. They are considered as ‘meshes’ and can be displayed with hide, shade and render effects. To demonstrate using some of these objects: 1 Open your MV3DSTD template file, with MVLAY1 tab, layer MODEL, UCS BASE and the lower left viewport active 2 Refer to Fig. 21.1 and display the Surfaces toolbar 3 In the steps which follow, reason out the co-ordinate entry values 4 Select the BOX icon from the Surfaces toolbar and: prompt Specify corner point of box and enter: 0,0,0 ϽRϾ prompt Specify length of box and enter: 150 ϽRϾ prompt Specify width of box and enter: 120 ϽRϾ prompt Specify height of box and enter: 100 ϽRϾ prompt Specify rotation angle of box about Z axis and enter: 0 ϽRϾ 5 A red box will be displayed at the 0,0,0 origin point 6 Menu bar with Draw-Surfaces-3D Surfaces and: prompt 3D Objects dialogue box respond pick Wedge then OK prompt Specify corner point of wedge and enter: 150,0,0 ϽRϾ prompt Specify length of wedge and enter: 80 ϽRϾ prompt Specify width of wedge and enter: 70 ϽRϾ prompt Specify height of wedge and enter: 150 ϽRϾ prompt Specify rotation angle of wedge about Z axis and enter: ؊10 ϽRϾ 7 At the command line enter CHANGE ϽRϾ and: prompt Select objects and pick the wedge then right-click prompt Specify change point or [Properties] and enter: P ϽRϾ prompt Enter property to change and enter: C ϽRϾ – colour option prompt Enter new colour and enter: 14 ϽRϾ prompt Enter property to change and ϽRETURNϾ 8 Using the icons from the Surfaces toolbar, or the 3D Objects dialogue box, create the following two 3D objects: Cone Cylinder (using cone object) Base centre: 50,70,100 Base centre: 75,0,50 Radius for base: 50 Radius for base: 50 Radius for top: 0 Radius for top: 50 Height: 85 Height: 90 Number of segments: 16 Number of segments: 16 Colour: green Colour: blue 9 Restore UCS RIGHT and with the ROTATE icon from the Modify toolbar: a) pick the blue cylinder then right-click b) base point: 0,50 c) rotation angle: 90 Chapter 21 3D objects [...]... squares, then draw the following four lines: line start point next point colour 1 25, 25, 180 @0, 5, Ϫ30 blue 2 75, 25, 180 @5, 0,Ϫ30 green 3 75, 75, 180 @0 ,5, Ϫ30 cyan 4 25, 75, 180 @0,0,Ϫ60 magenta 6 Change the viewpoint in the 3D viewport with VPOINT-ROTATE and angles of 300 and 30 The model will be displayed as Fig 22.7(a) Extend 1 With the 3D viewport active, restore UCS RIGHT and select the EXTEND icon from... (rectangular) command with the 3DGEOM model 147 148 Modelling with AutoCAD 2004 5 With MVLAY1 tab active, zoom-centre about the point 170,110,1 85 (why these co-ordinates) at 400 magnification (55 0 in 3D view) 6 Hide the model – Fig 22.4 then Gouraud shade the 3D viewport 7 Try the 3D orbit command with the shaded model 8 This exercise does not need to be saved Polar 1 Open 3DGEOM, UCS BASE with the Model tab... ALIGN command using two 3D objects 149 150 Modelling with AutoCAD 2004 2 Using the Surfaces toolbar create the following two 3D objects: Box Wedge corner 0,0,0 160,0,0 length 100 100 wedge 80 80 height 50 50 rotation 0 0 colour red blue 3 Copy the box and wedge: a) base point: 0,0,0 b) second point: @ 150 , 150 4 Set the running object snap to Intersection 5 Menu bar with Modify-3D Operation-Align and: prompt... [Project/ Edge/Undo] respond pick blue line 1 then right-click/enter 151 152 Modelling with AutoCAD 2004 2 Repeat the EXTEND command using the entries E,E,P,U as step 1 and: a) extend the green line 2 to edge bc with UCS RIGHT b) extend the cyan line 3 to edge cd with UCS FRONT 3 The extended lines are displayed as Fig 22.7(b) Trim 1 Still with the 3D viewport active, restore UCS BASE and select the TRIM... OK 155 156 Modelling with AUTOCAD 2004 Figure 23.2 Block definition dialogue box for SQ1 2 The green coloured square will be ‘made into a block’ and should disappear from the screen due to respond 4 in step 1 3 Using the Block Definition dialogue box, make the other three blocks using the same method as step 1 with the following information: first second third name SQ2 PAWN ROOK insertion pt 0,120,0 150 ,0,0... active, i.e tick 5 Rotation angle: 0 6 pick OK and the red body will be displayed at the 0,0,0 insertion point 161 162 Modelling with AUTOCAD 2004 Figure 23.7 The completed wall clock created from inserted wblocks 5 Activate the Insert dialogue, select the Browse option and insert the other wblocks with the following information: File name: FACE DIAL Insertion point: 0,Ϫ40,130 0, 55 ,130 X scale: 1... 20 radius: 25 width: 80 width: 10 colour: magenta height: 60 height: 60 colour: red colour: blue cylinder cone centre: 50 , 50 ,0 centre: 50 , 50 ,70 radius: 8 radius: 12 height: 70 height: 20 colour: green colour: green 4 When the palace layout is complete, hide and shade 5 Save the complete model as MODR2004\PALACE It will be used in a later activity 141 Chapter 22 3D geometry commands All AutoCAD commands... is now aligned as required – Fig 22.1(c) 5 Select the ARRAY icon from the Modify toolbar and with the Array dialogue box select: a) Type: Polar Array b) Objects: the blue wedge c) Centre point: X: 50 and Y: 50 d) Method: Total number of items & Angle to fill e) Total items: 4 f) Angle to fill: 360 g) Rotate items as copied: active 143 144 Modelling with AutoCAD 2004 6 The blue wedge is arrayed to the...140 Modelling with AutoCAD 2004 10 Restore UCS BASE 11 Create another two 3D objects: Dish Torus Centre of dish: 75, 60,0 Centre of torus: 75, Ϫ90 ,50 Radius: 60 Radius of torus: 100 Longitudinal segments: 16 Radius of tube: 20 Latitudinal segments: 16 Tube segments: 16 Colour: magenta Torus segments: 16 Colour: cyan 12 With UCS RIGHT current, select the ROTATE icon:... lines: a) line 1, start point: 150 ,0 next point: @0,0,40 b) line 2, start point: 200,0 next point: @0,0, 15 c) line 3, start point: 250 ,0 next point: @0,0,8 159 160 Modelling with AUTOCAD 2004 6 The three wall clock components will be created as tabulated surface models, so set SURFTAB1 to 16 7 With the TABULATED SURFACE icon from the Surfaces toolbar: prompt Select object for path curve respond pick . the level 2, 3 and 4 contours. My values were, with UCS BASE current: ptA: 55 .06, 101 .57 , 50 ptB: 95. 42, 101.91, 100 ptC: 127.07, 65. 65, 1 25 b) With layer PATHDOWN current, create a 3D polyline. (rectangular) command with the 3DGEOM model. 148 Modelling with AutoCAD 2004 5 With MVLAY1 tab active, zoom-centre about the point 170,110,1 85 (why these co-ordinates) at 400 magnification (55 0 in 3D view) 6. point: 70,70,100 85, 70,1 25 Endpoint: 80, 35, 100 90 ,50 ,1 25 Endpoint: 130, 45, 100 130,60,1 25 Endpoint: 170,90,100 130,80,1 25 Endpoint: 100,120,100 close Endpoint: close 6 Menu bar with Modify-Object-Polyline