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Analyzing Landscapes in CAD

Once you have modeled a landscape in a three-dimensional modeling package, many questions can be explored regarding views and shadows, and analytical drawings, such as sections, can be easliy made.

This lab includes the following exercises:

  • Analyzing Views from specific locations
  • Cutting Sections
  • Analyzing Shadows

Download the tutorial Data Set

Today's tutorial dataset includes another version of the Starvegoat dataset that includes some trees and a representation of the oil storage tank. Right-click to download and extract the included files to your c:\temp directory.

Analyzing Views from Specific Locations

Setting up specific views is covered in the FormZ modeling manual and in the Khemlani book. I have found that in setting up views to be made from eye-height at soecific places, it is useful to begin by making a new layer named 'viewers' and adding some simple cylinders about 5'8" in height. These will mark the locations of your vierers, and provide some reference in the Cone of Vision editing tools. I also find that it is helpful to turn off all layers except for the viewer and something that represents the target.

In this exercise, we will try to determine if the berm behind the beach in the starvegoat model is high enough to block the view of the oil tank.

  • Create a viewer on the island.
  • Turn off all layers but the viewer and the tank
  • Set view to axonnometric
  • Use the Views->Cone of Vision tool to set up a view from the viewer to the top of the tank.
  • Experiment with perspective views and different focal lengths.
  • Return to normal model view
  • Is the tank visible?

Cutting Sections

Section views are important tools for showing particular aspects of three dimensional proposals. In FormZ, a good way to cut a section is by adjusting the cone of vision and clipping the view on 'Hither and Yon'. On our model it is interesting to cut a section that follows the same line as our viewpoint on the island, through the tank. THis section could show us where, and how high, we could create a visual barrier to mask the view of the tank.

  • Create an axonometric view of your site with the viewer and the objective above the ground level.
  • In the Plan view, adjust the viewer the hither plane of your cone of vision (which in the case of an axonometric is a rectangular prism) to align with your previous view line -- from the island to the tank. This is where your section will be cut.
  • Extend your 'yon plane' to encompass the area beyond your section that you want to see.
  • Play with the height of your sight-line to reveal more or less of the surface behind your section-cut. Keep the line paralell with the xy plane, otherwise your section won't be vertical (which is always assumed of sections)

Analyzing Shadows

One of the most useful things about working with landscape designs in a 3d moddeling package is the ability to analyze shadows. Understanding the interplay of sunlight with your interventions is something that is difficult to do with manual methods, and now that there is an easy process for doing this, there should be no excuse any longer for courtyards, entrances or other spaces that are too shady or too sunny.

  • Select your light source from the lights palette.
  • Set your shadow type to Hard Raytraced or Soft Mapped the accelerated option doesn't work for our coordinate space.
  • Set your Light Direction from Sun properties for the local place, and an interesting time.
  • observe the effect of shadows on your site. Note that our trees don't look interesting in plan view. YOu should use an oblique view for this.
  • If you want to create a quick anomation of a shadow study, export images in a sequense into a new empty folder. The sequense of your images should correspond with the alphabetical order of your file names. note that aplphabetical order would put 12noon before 9am!
  • Use adobe imagetready to Import Folder as Frames and save as an animated gif.