Final Design

Final Design

The final design focused on creating a reliable and accurate process for the replication of the Amorphophallus titanum, that can later be adapted for the Rafflesia Arnoldii. The Amorphophallus titanum was separated into three main areas of focus, the spadix, spathe and male/female flowers, which can be seen in figure 1 below.

Figure 1: Names of Each Section of the Amorphophallus titanium

Images sources: http://botanicus.org/page/441733 (main flower); http://www.thegorgeousdaily.com/amorphophallus-titanum/ (Male/Female)

When adapting the process for the Rafflesia Arnoldii, the suggested section separations are the perogone lobe, perogone tube, and diaphragm. The figure below shows the each of the suggested sections for the Rafflesia Arnoldii.

Figure 2: Names of Each Section of the Rafflesia Arnoldii

Images sources: http://www.rbge.org.uk/the-gardens/edinburgh/inverleith-house/archive-exhibitions/inverleith-house-archive-main-programme/2009/raffles-ark-redrawn

http://biocurioso.wordpress.com/2012/12/07/qual-e-a-maior-flor-do-planeta/rafflesiaarninside/

http://kingdomjason.wikispaces.com/Kingdom+Plantae

The process created, generates a computer generated 3D model by either using a 3D scanners and/or Structure from Motion (SFM) technology, which in turn get cleaned and edited using various file manipulation techniques, and then replicated using a CNC mill or 3D printer, as shown in figure 3 below.

Figure 3: Flowchart of Replication Method

Generating the 3D model

The 3D model was generated by either using a 3D scanner or SM technology. Three different types of 3D scanner were explored for generating 3D models, the Trimble TX5, NextEngine, and the Cubify Sense.

There are a variety of 3D scanner that are used in order to create a computer generated 3D model. This is done by utilizing lasers and reflected light to generate point clouds or polygon meshes. Typically scanning equipment falls into the following two categories.

• Time-of-flight: A light impulse is sent from the scanner to the object and reflected back to the sensor. Timing how long it takes the beam to return to the sensor and knowing the speed of light the distance to the object can then be calculated

• Triangulation: is Performed when a reflection of a laser light or point is captured by a sensor located at a known distance from the laser's source. Thus the resulting reflection angle is interpreted and allows the scanner to determine the 3D measurement of the object.

Triangulation Based Scanning Time-of-Flight Scanners

• Structure from Motion (SFM) - SFM is a software based method using a series of algorithms to construct a 3D point cloud model from a series of 2D images. These algorithms deduce the location of the camera based on the different orientations of the object in each photograph. The points are extrapolated from each image and are matched to alike points from other photographs. These points are then aligned to generate the 3D image.

SfM

In the video below, the scanning of the full-scale flower models using the Trimble TX5 can be observed.

Video 1: Scanning with Trimble TX5 3D Scanner

The Agisoft Photoscan Pro SFM program was used for generating the 3D models. Figure 4, shows the 3D model of the spadix being generated using SFM technology in Agisoft Photoscan Pro. The 3D model, represented as a point cloud, is shown in the center. The blue boxes around the 3D model, represent the photo alignment and correspond to the original photos at the bottom.

Figure 4: Agisoft Photoscan Pro Generating 3D Model

File Manipulation

Once the 3D image has been generated, there are remaining voids or holes left in the part as well as ambiguous points that must be removed. The following two software packages were utilized for this process:

•Meshlab mesh processing system: Compatible with multiple files, can section, invert, extrude, fill holes, decimate, and delete points from images.

•ZBrush digital sculpting and painting: Compatible with *.obj and *.stl files, can fill holes, section, delete points, and repair and smooth out images.

Figure 5: Meshlab Sectioned and Inverted Image

Figure 6: Zbrush Cleaned and Repaired Image

Manufacturing Methods

The male/female flowers were recreated by the 3D printing method, while the spadix and spathe were recreated by CNC milling, using the KUKA 6-axis robotic CNC milling from Robotic Solutions Inc. The spadix was CNC milled using the first technique, of milling a positive mold. The spathe was created using the second CNC milling technique by creating three part mold, using negative molds.

CNC Milling Method

Video 2: Milling of Spadix with KUKA CNC Robotic Mill

The spadix was milled as a positive mold from the 3D model of the spadix obtained from the 3D scanner and SFM software. Low density 2 lb. EPS foam was used for the spadix and milled into 3 sections which were glued together. The spadix was scaled to a height of 1.5748 m (62 in), to replicate the actual size. The figure below shows the final result of the milled spadix.

Figure 7: Final Milled Spadix

Due to the thin structure the spathe, it was ill-suited for being milled as a positive. As such an alternative method of production was to create a mold to be used for casting or layups. Due to the intricacy of the edge of the image it was difficult to create a common plane for which to split the mold. A three part mold was establish that was well suited for structure of the spathe, and was created using the following process:

•Import cleaned and repaired image into Maya 3D animation software

•Delete polygons around rim of spathe along the interface of the inside and outside of image

•Separate image

•Invert and extrude images to create mold using Meshlab

Figure 8: Final Case of Spathe

3D Printing Method

The male and female flowers presented a unique problem, because despite all of the 3D capture methods visited, none were capable of accurately capturing these smaller details, as can be seen in the 3D image capturing table. Fortunately as seen in figure 9, there is a naturalistic pattern in both the male and female flowers.

Figure 9: Naturalistic Pattersns of Male/Female Flowers

As such, small sections of the flowers can be scanned and imported into a 3D imaging software and replicated producing a digitally created pattern mimicking the naturally created one. The resultant can then be printed.The male/female flowers were constructed using Solidworks and then 3D printed. Figure 10 below, shows the final results of the 3D printed model of the male/female flower.

Figure 10: Final 3D Printed Model of Male/Female Flowers