COMPUTER AIDED ARCHITECTURAL DESIGN
Workshop 9 Notes, Week of November 1, 2010

Projections,  Clip Planes and 3D Human Figures

PART I: GENERATING A PDF PRINT IMAGE AND CUT SECTION

• Goto the File >  Print Dialog Box. And using the magnifying glass icon (see arrow below), open the driver for  pdf.plt  created to "print" to a pdf file rather than directly to a printer.
   
  
  
  
  
• Select the window you wish to print from in the view text box (e.g., "view2" in upper-left corner of dialog box above).
•  Use the maximize option or set paper scale (e.g., 15 paper in  to 1 feet in model in above example) .
• Goto File Print dialog and create the  PDF file.
• Edit or Review in the PDF file Adobe Reader or Acrobat. Note, vector graphics holds resolution in transferred formats.
  
  

• Select to "on" the check-box for the  "Plot to 3D" dialog option within Print Dialog Box
• Note that the preview image is shaded.
• Follow remaining steps as outlined in previous example.
  
  
  
  
• Edit or Review the PDF file  in Adobe Acrobat (not Adobe Reader). Note, vector graphics holds resolution in transferred formats.
  
   

• Use various tools to rotate, zoom in and pan the model, change from perspective to axonometric rendering, and to explore different lighting options.
• Use sectional viewing  tool to create cut plane and determine visibility of model.

• Go to File/Export/Export UCD and save the file.
• Go to Adobe Acrobat Professional and load in the file using the advanced editing tools.
• To load the file, use Tools/AdvancedEditing/3dtool and place a rectangle in the PDF file. First place the rectangle and then the browser opens for retrieving the file.
• Now use the same tools as in  the previous example to rotate, zoom, pan and section the model.
  

PART II: 3D Human FIgures

1. Transparency Maps. 

• Download the sampe tif  files in the folder on examples\materials2.
• In the visualization task open the Material Editor, Create a new Palette file call mypeople, and a new material named myperson using methods already explored in workshop 8. 
• Select the pattern map dialog box.

• Use the directory shortcut icon to locate the materials2 folder downloaded from classes, and select person04.tif

• In the "Pattern"  dialog box that follows, set the units  to  "surface", mapping to "Parametric" and select on the "Transparent Background" check-box.  Note that by selecting the "Transparent Background" check-box, the field of black pixels surrounding the figure are converted to a transparency key.

Right-click on the material  and assign it to the vertical  places above the cube in the drawing. 

• The resulting rendering of the image as rendered by  raytrace will include shadow maps for the figure.; however, this is only effective from a point of view that looks frontally upon the image. The technique is less effective when the 2D surface is viewed from other angles.

• Similarly, a transparency map of a tree can be assigned to two rectangles at cross-axis to create a somewhat more 3D  illusion, but has limitations when viewed from alternative viewing angles. 
• A rectangle is placed on the orange cylinder in the image below .
• A rotated 90 degree copy is based on the center of the upper edge of the rectangle.
• The transparency map of a tree is obtained from the materials images and assigned to the rectangle.

2. RPC FILES

RPC files are provided by commercial retailers who will occasionally provide samples. These files will reorient to the view desired and thus are better suited for three-dimensional viewing. Commercial sites for obtaining such figures include  http://www.archvision.com/.  

• Download the RPC files in the classes folder under examples\rpcfiles.
• Select the tool  "Place RPC" from the Visualization task.

•  Within the "Place RPC: dialog box, Use the magnifying  glass icong adjacent to the "directory" text box  and  browse to select the " rpcfiles" folder.
  
  
• Within the "Place RPC" dialog box, open the category People (Casual), and select "Lisa (1/2 resolution).
• Enter two data points in the view window to place and rotate the figure.
  
  
• Rendering this figure will consistently orient to a 3D view from any view angle.
  
  
• These files can consist of a number of images or frames that provide varied views syncronized with each new view orientation towards the model.
• Some of the RPC image  have front and rear points of view, such as the Category "Demo" image "Penny" that is depicted with a side and front profile in the image below.
  
  
  
•  The rendering of this figure varies from front to rear such as in the case of two instances facing in opposite directions below.
• Other examples include automobiles and chairs.
  
  
  
  
  

• Note that two renderings from different camera positions capture the RPC figure in 3D. However, the first figure of the man developed through transparency mapping appears paper-thin when viewed from some angles. For example, compare the first and second figures below.
  
  

G:\Arch541-Mark-F08\Examples\people\simplerpcfiles

3. 3D WAREHOUSE

Microstation's implementation of 3D Warehouse allows direct insertion of 2D and 3D  figures(saved  in the sketchup format) into a 3D model. The dialog box under the utilties menu goes to a web search engine for grabbing 3D and 2D human figures as well as other objects. Some of the 3D objects  may add substantial rendering time to a model, but have the advantage of being  more easily adapted to different views of the model. Note, the option selected under 3D Wharehouse should be "Import as Model". The 3D Wharehouse links to web site that provides many different downloadable 3D models. The example below was provided by searching under "people" and then choosing "Assorted People 3D" authored by "Distressed American. (The "Place as Cell" option would create a instance of object from a "Cell" library, something we haven't covered.)

• The method used above places the files in a second model. A Microstation session can host more than one model at a time.
• Use the File/Models menu to access the two models.
• Copy some figures from the plan view of the people model to the plan view original model by using the copy and paste options.

PART III: USING THE VOLUME CLIPPING PLANE

1. CLIPPING VOLUME

• In the "view Attributes Dialog Box", turn on the  volume clipping plane option.
  
• Place a solid cube on a separate layer that partially intersects with the model.
• In the view window controls,  select the "Clip Volume" icon (2nd from end, icon with scissor in image below) and pick the cube.
  
  
  
  
• The model is now clipped according to the placement of the volume. You can move the cube to change the part of the model that is impacted. That is, all the parts of the model outside the cube are clipped away. Only those parts of the model inside the cube are visible.
  
  
  
  
• Within the Clip Volume, dialog box, select the second icon from the right-hand side to turn off the visibility of the clipping volume. (Alternatively, for the perspective view, you may want to turn off the layer which holds the cube.)
  
  
  
  
  
  
• This also ensures that the objects (e.g, the box, cylinder and truncated cone)  within the clipping volume are  visible when the view is shaded.
  
  
  
  PART IV:  ADDITIONAL VIEW OPTIONS IN PDF FILES
  
  1.  USE THE SECTIONAL TOOL on 3D PDF FILE

• Open up Adobe Acrobat Professional and load a 3D PDF file created by one of the methods above.
• Use sectional viewing  tool to create cut plane and determine visibility of model.