1.2 Intro to Parametric Modeling: Manipulating Terrain

Department of Landscape Architecture COMMANDS:
Graduate School of Design
Harvard University

INSTRUCTIONS:

1.2_ Intro to Parametric Modeling: Manipulating Terrain

September 14, 2011

T opics C o v e r e d : SOFTWARE:
1. Representational analogs for terrain and topography
Rhino, Adobe Illustrator
i. Contour plan or model Rhino, Adobe Illustrator
ii. Sequential sections Rhino, Adobe Illustrator
iii. Spot elevations or point clouds
iv. Meshes Rhino, Grasshopper, RhinoTerrain
v. Shaded relief
2. Parametrically manipulating terrain
i. Attractor-based simulations
ii. Patterning with image heightfields
iii. Parametric patterning

INSTRUCTIONS: COMMANDS:
Representational analogs for terrain and topography
1. Building upon the GIS-generated surface analogs discussed last Contour (Curve menu > Curve from Objects > Contour) Perform from
Front viewport for plan contours with Ortho mode on.
week, this week we will look at ways of drawing landform that Use “Week 3 - color gradient contour.gh” to apply a color gradient to
assist in expressing its fluidity and dynamic nature. Central to this contours. To export to Illustrator, File > Export Selected > select AI
discussion is the idea that all reproductions of landforms in nature Contour (Curve menu > Curve from Objects > Contour) Perform from
or design environments are analogs. That is, they are abstractions: Top viewport. Optional: In Illustrator, change the stroke to fill to show a
reduced so as to accurately convey some singular property of solid section profile
landform (such as slope, contour interval, structure, materiality, etc.). Open “Week 3 - points for exporting to AI.gh” in Grasshopper. Select
2. Surface/Landform Analogs: the points you wish to show in Illustrator. Open the file in Illustrator and
invert the stroke and fill.
i. Contour/grading plan or contour model

ii. Sequential sections

iii. Spot elevations or points: You cannot bring point objects into
Illustrator because they cannot display a stroke or a fill. You
must first apply a small circle to each point that can be filled
in. Grasshopper makes this very simple.

INSTRUCTIONS: COMMANDS:
iv. Meshes
For meshes, simply export the mesh surface to Illustrator. (File > Export
v. Shaded Relief (Hillshade) Selected). For surfaces, ExtractWireframe (Curve > Curve from Objects
> Extract Wireframe) and then export. It also helps to extract the mesh
Parametrically Manipulating Terrain or surface outline: MeshOutline (Curve > Curve from Objects > Mesh
1. Open “Week 3_start.3dm,” found at goliath.design.harvard.edu\ Outline) or DupBorder (Curve > Curve from Objects > Duplicate Border)
Render. It helps to add a directional light as well (Render menu > Create
Public\Courses\2241\2011\Tutorial Base Materials\Week 3 - Directional Light) to give highlight and shadow. Adjust the Shadow
Manipulating Terrain Intensity of the light (Properties window > Light > Shadow Intensity). If
2. Create a rectangle that is 4000 m long by 3000 m tall. Move the you are going to combine the rendering with linework, make sure your
rectangle to a place on the landform that you find topographically or background is transparent in Tools > Options > Rhino Render
contextually interesting.
3. Drape points over the RhinoTerrain landform within the rectangle. File > Open
4. So the points you created are more easily visible, adjust the way that
Rhino displays points in the Shaded Viewport. Rectangle (Curve menu > Rectangle > Corner to Corner)
5. Grasshopper is a plugin for Rhino that allows you to link several Move
different operations and commands together in a process or DrapePt, Set Spacing=5
flow chart (called “Spaghetti Wiring” to Grasshopper users). By Tools > Options > Appearance > Advanced Settings > Shaded > Objects >
incorporating numeric sliders and automatically recalculating Points, set Point Style to ‘Solid Square” and Point Size to 1.
solutions, Grasshopper allows you to design parametrically in Rhino.
That is, unlike Rhino’s native capabilities, which almost always Grasshopper
require you to remodel something in order to edit it, Grasshopper
enables an endless number of permutations, and does so quickly. For In Grasshopper: File > Open
more information on Grasshopper, see the PDF manuals in the 2241
folder on Goliath. Open Grasshopper.
6. Attractor-based simulation:

i. Open “Week 3 - basic attractor.gh”
ii. Follow the notes on the yellow stickies to adjust the

parameters

1. 3. 1. Right click on the box that says Pt and Set Multiple Points, then
2. select the points you just made in the Rhino window

2. Right click the box that says Attractor 1 and Set One Point, then
select one of the points on the Point Attractors layer. You can move
this point around if you like by dragging it. (make sure to try moving
it up and down along the Z-axis as well)

3. Drag this slider to adjust the falloff radius around the attractor point
that affects how much of the surface is changed.

INSTRUCTIONS: COMMANDS:
7. Patterning with Image Heightfields
Heightfield (Surface menu > Heighfield from Image)
i. Create a surface from an image in Rhino using Heightfield from Sample Points: 500x500, Height: 100 inches, Interpolate Points
Image. Select one of the images on Goliath or use your own. In Grasshopper: File > Open
Use the rectangle you previously drew as a guide. Images for
heightfields work best when they are black and white, high- In Grasshopper: File > Open
contrast (white forms a hill, black a valley). Blurry images
produce smoother results while sharper images produce
sharper landforms.

ii. Open “Week 3 - mesh plus surface addition.gh”
iii. Follow the notes on the yellow stickies

1. 1. Right click on the box that says Pt and Set Multiple Points, then
select the points you just made in the Rhino window
2.
3. 2. Right click the box that says Srf and Set One Surface, then select the
surface you just made with Heightfield from Image

3. Drag this slider to adjust the multiplier for how intensely the
Heightfield from Image surface affects the original surface

8. Parametric Patterning In Grasshopper: File > Open
i. This exercise uses Grasshopper to create a 2D pattern from
which you will generate a heightfield that affects the original
landform as in the previous step.
ii. Open “Week 3 - landform patterning.gh”
iii. Follow the notes on the yellow stickies

1. 1. Create a point object at the bottom left corner of your rectangle in
Rhino. Right click the Pt box and Set One Point. Adjust the sliders to
2. control the size and extent of the rectangular grid.
3.
2. Right click the box that says Attractor 1 and select a point on the
Point Attractors layer, or create your own, and Set One Point.

3. Drag this slider to adjust radius of the resultant shapes (circles,
polygons, and rectangles are created, select one of those boxes to
highlight one set).

4.

iv. Experiment with different shapes, sizes, and patterns and 4. Adjust the sliders for the rectangular fillet, number of polygons, etc.
make your own 2D pattern (see detailed instructions at right). When you are satisfied with a geometry, right click one of the layers
and Bake.
v. Once you have settled upon a 2D pattern, Bake it into Rhino.

INSTRUCTIONS: COMMANDS:
vi. Select the pattern you have created in Rhino and export it to
Illustrator. File menu > Export Selected > select AI from pulldown menu
vii. Open the file you just made in Adobe Illustrator. Select all of
the shapes and in the toolbar, click the arrow at the upper Swap fill and stroke shortcut: Shift+X
right of the stroke and fill colors to swap the stroke and fill
colors (e.g. change the objects from having a black stroke to
a black fill):

viii. You can also apply a radial gradient to the shapes. You will be Gradient palette > Type = Radial, adjust color sliders
using this pattern as the basis for another Heightfield from
Image surface in Rhino, so applying a gradient to the shapes
will result in a smoother heightfield surface.

ix. Save the AI file and open it in Photoshop. Illustrator: File > Save, Photoshop: File > Open (Make sure “Files of
x. Create a new layer behind the current layer in Photoshop, Type” is set to All Formats)

and fill in the background with black. Set background color to black (RGB=0,0,0), Control+Backspace to fill
xi. Export the file as a JPG. Keeping in mind that smooth, layer with background color (Command+Delete on a Mac)

gradient like transitions create smoother landforms in File > Save As (Save as JPEG)
Rhino, while high-contrast, sharp edges create more defined
landforms in Rhino, your image may look something like this. Filter > Blur > Gaussian Blur (a value of about 3-4 pixels should be
You may want to apply a Gaussian blur before exporting so sufficient)
the image is even smoother.

xii. Go back to Step 7 of this handout (Patterning with Image
Heightfields), using the image you just created to affect
your original surface. Use the resulting surface to generate
contours, point clouds, etc. as described at the beginning of
this handout.