# Week 2 - Computational-Aided Design

## Build a 3d

The work consists of making a design in 2D and turn it into 3D by various techniques.

## 2D DESIGN

IDEA AND DESIGN

My final project will be a surfaces that moves. I want to create a gif with this movement.

First I'm going to use Photoshop, I draw layer by layer the movement, but first I make a sketch with all the movements. I use a wacom cintiq tablet because is so useful to make scketches and I use with photoshop with a lot of my works.

In Photoshop I will make a layer for each line motion. Them I use the "line time" to make a gif. To do that I put each layer turned on for each step of the time line.

In Photoshop lines are drawn by hand, have no real deformation. Therefore I will use Grasshopper. I use a catenary, it's a line that have an interaction with a gravity force. It's a similar process that I use with the 3D of this assigment but only in 2D. I will use Kangaroo, a plugin of Grasshopper in Rhinoceros 3D.

I've drawn a line which I have applied forces. I can choose the definition of the curve. With more definition more deformation. (see the gif). I set the definition with the division of the curve. I used the Kangaroo setting panel to have get more steps in the deformation of the curve.

## 3D DESIGN

IDEA AND DESIGN

My idea is to create an object that reacts to external forces, such as gravity. I will use one program and some plugins. Rhino can create, edit, analyze, document, render, animate, and translate NURBS. With Rhinoceros 3d I make the surfaces. Grasshopper is a Rhino plugin. It is a very complex plugin that can be installed other plugins. In this case I will use Kangaroo Physics, which is a plugin for physical simulations of objects. The idea of using Grasshopper and Kangaroo is parameterize and simulate all data and to control the geometry.

First I will explain the design process. To design a surface that receives external forces like gravity and its own weight we have to take into consideration that it will need anchor points. When the surface receives the force of gravity, it will have a deformation which depends on the composition of the surface. Grasshopper allows us to modify these parameters, making the surface more or less deformed. To find the parameters of deformation of a material we have to do tests on a test bench or ask the manufacturer. In this case these parameters will be entered by hand.

1) Using Rhino I make a very simple surface to find the anchor points. Anchor point is a point into the surface that won’t move.

2) Introducing forces on the surface which will deform. I use the plugin Grasshopper for Rhino and the component Kangaroo. I have read the Arturo Tedeshi's book called AAD ALGORITHMS-AIDED DESIGN |PARAMETRIC STRATEGIES USING GRASSHOPPER.

Here is the Kangaroo forces panel. I can choose some options. The connections are the lines that are connecting two points for the spring to actuate between them. The stiffness is the rigidity that will be affected by surface forces, the rest length is the length that the spring will try to reach. The plasticity is the maximum elastic deformation. In this case I choose 0.

3,4,5) Increasing the difficulty. Now I'm working on a more difficult model with more surface and an internal structure, more or less as the one I want to make in my final project. It will be rendered in 3dsMax with Vray render engine. To make the render I choose a very simple material and a simple light. The outer material is a little transparent, and the rest will be opaque with some shine, all will be based white color.

I captured the screen to make the gif, I used an online tool called Ezgif.

This is the process and the gif I make

 Snapshot of the RhinocerosĀ“s with the simple surface
 Select anchor points
 Surface springs
 form finding
 more complicated structure, in this case I used a multiple surfaces, they're joined, when the force is applied it deforms jointly.
 final form finding
 gif 01
 gif 02
 Video 03
 Render 01
 Render 02

Making this model I realized that to create a physical model I need a long time, so I'll start designing my final project with a simpler object.

 COMPUTER-AIDED DESIGN Modelled experimental objects/part of a possible project in 2D and 3D software x Shown how you did it with words/images/screenshots x Included your original design files x

FILES:

2D Photoshop + rhino + gh .