AutoCAD solid modelling - 3

Introduction

Select: View - Tiled Viewports - 2 Viewports, and then press to accept a vertical split line.

This tutorial will bring together the concepts and commands introduced in the previous tutorials. You'll create two rooms and then produce a rendered image of the result. It should take between 60 and 90 minutes to complete.

Start AutoCAD, display the Solids toolbar (if necessary), and split the screen into two vertical viewports.

Drawing Limits and Units

The previous tutorials used the default drawing, without regard for sizes; this tutorial creates rooms so it's necessary to define the "virtual space" before creating the objects. Select Data - Drawing Limits, AutoCAD will prompt for the "lower-left corner" press

to accept the default (0,0), then type 20000,20000

for the "top-right corner". Select Data - Units and set Precision to "0". Finally, select View - Zoom - All.

Or type: limits

Zoom All

Create Layers

Select Data - Layers, type walls in the text input field, select "New", then select WALLS in the layer name window, select "Set Color..." and choose a (bright) colour, select OK (to dismiss the colour dialog).

Still in the layers dialog, type ceiling in the text input field, select "New", then select CEILING in the layer name window, select "Set Color..." and choose a (bright) colour, select OK (to dismiss the colour dialog).

Type floor in the text input field, select "New", then select FLOOR in the layer name window, select "Current", select "Set Color..." and choose a (bright) colour, select OK (to dismiss the colour dialog), and finally, select OK (to dismiss the layers dialog).

Don't forget to make the Floor layer the current layer...

Draw the Floor

This tutorial will use the second technique. The outline of the floor will be drawn in 2D, to make it easier to create the walls, then the floor will be converted into 3D.

Draw the outline of the first space.

There are generally two ways you might create a simple shape like a floor: either create the shape using box(es) or draw the shape's outline and then extrude it to the required thickness.

Pick the polyline icon (or type pline ), pick a position (click the mouse button) near the bottom-left of the screen, then type:
@7000,0
@0,4000
@-2000,0
@0,4000
@-5000,0
c

c = close (this automatically joins the last point to the first point).

The Rectangle icon is under the Polygon icon on the Draw toolbar.

Pick the rectangle icon (or type rectang

), type: end

, and pick the top-right corner of the floor section just completed, for the other corner, type: @4000,-4000

Draw the Walls

Set the current layer to Walls.

Using the Box command...

Select the corner box icon (or type box

), type end

, and pick the bottom-right corner of the larger space, type @300,3900,3000

Select the box icon again (or press to recall the last command), type end, and pick the bottom-left corner of the larger space, type @7000,-300,3000.

Recall the command, type end, and pick the bottom-left corner of the larger space (again), type @-300,8000,3000.

Recall the command, type end, and pick the top-left corner of the larger space, type @5000,300,3000.

Recall the command, type end, and pick the top-left corner of the smaller space, type @4000,300,3000.

Recall the command, type end, and pick the top-right corner of the smaller space, type @300,-4000,3000.

Note that this distance is less than the length of the wall...!?

Recall the command, type end

, and pick the bottom-right corner of the smaller space, type @-1900,-300,3000

Internal Walls...

Recall the command, type end

, and pick the bottom-left corner of the smaller space, type @100,4000,3000

Recall the command, type end, and pick the same point and type @2200,-100,3000.

Turn the Floor layer OFF.

Look "under" Explode, in the Modify toolbar.

The "bottom" walls of the small space need to be joined togther. That will be done using the union command. Pick the union icon (or type union

), then select the two parts of the "bottom" wall of the small space and press

. This joins the two sections into one new (complex) solid.

Extrude the Floor

Turn the Walls layer OFF and the Floors layer ON (and make it the current layer).

Pick the extrude icon (or type extrude

), pick both spaces and press

, type -100

(for the extrusion height), and press

again to accept a taper angle of 0.

Create the Ceiling

Select the copy icon (or type copy

), pick both spaces and press

, pick in the middle of the spaces and then type: @0,0,3100

Change an object's layer

Select the change properties icon (or type chprop

), pick both spaces and press

, change their layer to Ceiling.

Add the Doors and Windows

Turn the Floors and Ceiling layers OFF, and the Walls layer ON (and make it the current layer).

The box's position does not need to be exact, but it should be thicker that the wall.

Create a box 1200x600x2100 (WxDxH) and place it near the middle of the "southern" wall of the larger space.

Create a box 600x1200x2100 and place it in the wall that separates the spaces. Then place a copy of the box in the "eastern" wall of the smaller space.

A Window

Create a box 600x2000x1600, then move the box up 500 so that the bottom of the box is at 500. Place the box in the "western" and "eastern" walls of the larger space.

Plan showing the Door and Window boxes in place.

Be careful that you pick walls...
if you make a mistake type "u" to undo the selection.

Select the subtract icon (or type subtract

), pick a wall, press

, pick the opening in that wall and press

. Repeat this process for each wall. It is important that each wall is done separately!

Place Some Simple Objects in the Two Spaces . . .

If you are not at UNSW, then you will first need to download the table and then access it (from your local hard-disk).
If necessary, (after inserting the object) move the table to the centre of the space (it doesn't need to be perfect).

Select the insert block icon from the Draw toolbar. Select "File...", change the drive to "R: Resources on EmuWater" and select the "samples\benv\autocad\r13" directory, pick "table.dwg", select OK (to dismiss the File dialog), select OK (to dismiss the Insert dialog). Place the table in the larger space, press

(don't change the length of the table), press

(don't change the width), type 90

(rotate the table).

download the chair

Use the same technique to insert a chair ("chair.dwg"). The chair back should be on the right. Place the chair at the table, then copy the chair to get two chairs on one side of the table. Next, use copy and rotate to place a chair at one end of the table. Then use mirror to copy those chairs to the other side of the table!

download the vase

Now insert a large vase, pick "vase.dwg", click on "Specify Parameters on Screen" (to de-select it), for the insertion point type 8500,6000,0, for the scale type 0.25,0.25,0.5.

Select copy, pick the vase, press

, type m

(for multiple), pick a point near the vase (as the "base point"), place copies of the vase beside each door (see figure below). Erase the "original" vase.

Plan showing the positioning of the table and vases.

Put a vase on the table!
Don't pick the insert icon.

Type insert

, type vase

, pick near the middle of the table, type 0.1

(X scale), press

(let Y = X scale), press

(rotation = 0).

Select move (or type m

), pick the vase, press

, pick near the vase, and type @0,0,750

, this should move it up onto the table!

download the bar

Finally use insert block to place a "bar" in the top left of the large space (remember to click on "Specify Parameters on Screen"). Once you've placed the Bar, you may want to move the table down a bit.

Turn all the layers ON and then save the drawing!!

Apply the Materials

Select the materials icon from the AutoVision toolbar (or type rmat

), select "Materials Library...", select some materials, for example:

	floor:	BUMPYWHITE STONE
	walls:	LIGHT WOOD TILE
	ceiling:	BEIGE PLASTIC
	table:	WOOD - WHITE ASH
	chairs:	BLUE METALIC
	vase:	PINK MARBLE or SOUTHWEST PATTRN
	bar:	WOOD - WHITE ASH

When you've selected enough materials from the library, select "OK" to close the library.

Carefully watch AutoCAD's prompts while you are doing this!

Attach the materials to the objects by selecting the material, clicking on "Attach", then selecting the object(s).

If you select the wrong object,
type u, to undo the selection.

If you have problems selecting the correct objects, turn some layers OFF.

We will need to alter some of these materials, but for the moment, we'll continue on...

Lights . . .

In a "more serious" model, you should create light fittings and then put the light sources in those fittings!

Select the light icon from the AutoVision toolbar (or type light

), make sure "Point Light" is the light type, select "New...", make the Light Name p1, set the intensity to about 1000, select "Modify", type .xy

, pick a position over the Bar (use a Z value of 2900). You can also turn shadows ON or leave them OFF. Select OK to dismiss the "New Point Light" dialog.

Create two more point lights in the same way. Place one over the table and the other in the middle of the smaller space.

Change the light type to "Distant Light", and select "New..." again. Call this light sun. The light's horizontal angle (azimuth) and vertical angle (altitude) are set on the right of the dialog box. Set the azimuth to -55 and the altitude to 35. Finally, turn the shadows ON.

Select "OK" to dismiss the "New Distant Light" dialog, and again to dismiss the "Lights" dialog.

Save the drawing!

Perspective . . .

This command (in my opinion) is really clumsy, but once you get the "hang" of it, it's workable!
Make sure that both points selected are inside the space.

Select View - 3D Dynamic View (or type dview

), pick the walls. AutoCAD will use the selected object(s) to help compose the view; press

, type po

(for points), for the TARGET, type .xy

, and then pick a position near the door joining the two spaces, AutoCAD will prompt for the Z (height) value, type 1500

. For the CAMERA, type .xy

(again), and pick a position near the bottom-left corner of the larger space, use 1700

for the Z value. AutoCAD will display the Walls in 3D wire-frame, type d

(for distance) play around with the distance but make sure you don't move out of the 0 to 1 range; note the appearance of the perspective icon in the bottom-left corner of the view, press

, to end the command.

If you move the "distance" to greater than 1, you are moving the camera further away from the target. This often moves the camera outside the space, which means that only the outside wall is visible!

If the view is quite restricted (and it will be), remove the second viewport, so the perspective takes the whole of the "screen".

If you still don't like your view, enter the dview command again, pick a few objects, and then type ta (to change the target position). This allows you to dynamically tilt and rotate the view!

Note that this "records" the view parameters, it does NOT SAVE THE DRAWING.

Type view

, then type s

(for save), type v1

for the view-name.

Save the drawing!

Type shadedge, then type 1 (one), then type shade. This shows how AutoCAD (without AutoVision) displays the space.

Rendering . . .

A "yucky" render!

Select the render icon from the AutoVision toolbar (or type render

). Make sure the Rendering Type is "AutoVision", the Scene to render is "current view", under Rendering Options make sure Smooth Shading, Apply Materials & Shadows are all turned OFF. Select "Render", the image should take up of a minute to generate.

Still pretty awful, notice the vases are rendered much smoother!? If they are not smooth, type facetres 2.

Press

(to recall render), select "Smooth Shading", and click on "Render". The image should take a bit longer up still only take a minute or so.

(Hopefully) a not so yucky render!

Press

(to recall render), select "Apply Materials", and click on "Render"; this image will take a bit longer again (but will still be fast).

Hopefully another not so yucky render!
But the materials are not that realistic, at present.

Also note that the shadows are not that convincing!

Press

, select "Shadows", and click on "Render"; now the image will take up to 30 minutes!

If you compare the last two images, you'll note they are quite similar. But, on my views, the chair seats in the second image were in shadow, whereas in the first image they were not. Obviously, turning shadows ON increases the rendering time considerably!

Fixing the Materials . . .

To return to the plan view,
type plan world.

Return to the wire-frame view (from a rendered view), type regen

As a "first fix", we will turn one of the materials around!

Select the mapping icon (or type setuv

), select the wall (with the door) separating the spaces, press

. The Mapping dialog will be displayed, select "Adjust Coordinates" and set the Plane to "WCS YZ Plane". This will turn the material so that its long edge faces the long edge of the wall. Select "Adjust Bitmap...", and then reset the Scale (near the bottom of the dialog) from u=1 v=1 to u=1 v=10, in other words change the Scale "v" value to 10! Select OK, three times, to dismiss the dialog boxes.

Select render, turn "Shadows" OFF(!), and click on "Render". This should produce a (more) realistic rendering of a timber veneer wall.

This is just the beginning! There is much more that you could do to improve the two rooms. Try to fix some of the other problems on your own...

Save the drawing!

Investigate...


Last Update : 13 October 2000 Major Revision : 29 October 1997 SEARCH . FBE SITEMAP		Disclaimer . Webmasters Page Contact : Stephen Peter Email : S.Peter@unsw.edu.au