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This weeks assignment objectives are to:

This week we were introduced to computer aided design (CAD). We looked at different ways to represent shapes specifically raster and vector.

Here are the programs I will use:

2D: Gimp (raster), Inkscape (vector) 3D: Fusion 360, Blender

I will first use gimp to replicate the sketch I did in power point for my project proposal. Thereafter, I will use Inkscape to modify a planthopper image and convert it to a vector. Following, I will use Fusion 360 develop a 3D model for my final project. Finally I will try Blender.

2D Modeling

Gimp

Gimp stands for Gnu image manipulation program Gimp is an open source software is a very popular raster program that is supposed to cover the functions of Photoshop.

https://www.gimp.org/tutorials/

File creation allows you to specify several parameters for example you can:

  • new file creation width y height px,
  • can select templates as well, and
  • Use different fills for the background
  • and export to different formats export (pdf, psv, etc)

The program allows you to modify the layout of your tool menu to suit your style of design.


Figure 1. Gimp menu
Figure 1. Gimp menu

To draw circles and rectangles it was a tedious process as it seems to be a three step process specifically:

selection tools (rectangle select) => select (send to path) => edit (stroke to path)

On the other hand to make lines was simple enough you select the brush tool and then you can just pick a point and thereafter press shift and move the cursor to where you want your line to end.

I liked the fact that has several layers, so it is easy to overlay objects on a background.

Also, it was interesting that even though I did not explore much that it allows you to play with the perspective of images and provides you with what would seem to be a transformation matrix.

a tutorial for beginners:

https://www.youtube.com/watch?v=YHwnlgD18kE

Figure 1. Gimp image of Intelligent Trap
Figure 1. Gimp image of Intelligent Trap

Note: some trouble that I ran into was that when I wrote text there was a frame with many points surrounding the text, however after you shift to another layer you will still see the text but no longer this frame.

Inskape

Is a graphics package that uses vectors to represent shapes. For this software I wanted to be able to use a picture of a famous plant hopper jump study and extract the outline and later use node editing to improve and simplify the image. For this purpose I watched two tutorials which focus on each part of the process:

vectorize an image with trace bitmap

edit paths by nodes


Figure . Planthopper study
Figure . Planthopper study


I loaded the image into Inkscape and then I used the trace bitmap function. I used a single scan option and the brightness detection option.

Then I press the apply button and with the node editing tools we can see all the nodes which were produced which are plenty. Subsequently, I applied the function simplify to reduce the number of nodes. Then I used the delete node tool to get rid of the floor as I only wanted the silhouette of the planthopper. Since, I needed to separate the legs and for these I used functions to add, join, substract, and separate nodes.


Figure . Planthopper siloutte
Figure . Planthopper siloutte
Figure . Planthopper nodes
Figure . Planthopper nodes
Figure . Planthopper simplified(nodes)
Figure . Planthopper simplified(nodes)
Figure . Planthopper legs separation
Figure . Planthopper legs separation

I watch the following 15 minute tutorial in Spanish which was quite informative.

https://www.youtube.com/watch?v=TKpchk09Rqg&t=588s


3D programs

Fusion 360

This week I spend quite a bit of time in Fusion 360. I learned a few things. One of them is that you can create several objects and have them as an assembly of objects. Also, I used offset planes that allow you to accommodate objects at distances from other objects keeping the same orientation.

Figure . Fusion image of Intelligent Trap 1.
Figure . Fusion image of Intelligent Trap 1.
Figure . Fusion image of Intelligent Trap 2.
Figure . Fusion image of Intelligent Trap 2.

Figure . Fusion image of Intelligent Trap 3.

I also tried to do some rendering in Fusion. I followed the this tutorial

https://help.autodesk.com/view/fusion360/ENU/?guid=GUID-0A159555-E362-4150-AE4F-E9E1308FEF40

In rendering one of the goals is to modify the appearance of the design. In order to render you need to change the mode tab from design to render. In this mode you can modify materials, appearance and environmental conditions. Note that appearance will override the materials. In regards to environmental conditions, you might want to modify the direction of the light the brightness etc. Below you can find some screenshots of the rendering of the object above.

Figure . Physical Material
Figure . Physical Material
Figure . Environmental Conditions.
Figure . Environmental Conditions.
Figure . Underside.
Figure . Underside.


Blender


Blender was definitely interesting, I started by watching the following tutorial:

https://www.youtube.com/watch?v=STGSzMfQFoA

Some commands I would like to remember were middle button for rotating the figure. Shift + middle button allowed us to move the canvas. Also the mode can be changed for concentrating in vertices edges and faces, this allows us to apply different commands to the specific geometrical features of the object. Also another command to remember is shift + A for adding meshes.

Figure . Blender image of Intelligent Trap
Figure . Blender image of Intelligent Trap


Preprocessing tools

Previously, I had used openCV for a course in computer vision. I tried to re install this software in my computer as I changed to a from an Intel based mac to a Silicon one and was not able to do so. This is a program that can work with python/C++ library and allows you to make image processing anything from resizing images to changing colors and image formats.

**Update I succeeded installing opencv. On python you can follow this tutorial:

https://www.youtube.com/watch?v=s-flQ28fJWc

First, you need to install python and thereafter the computer vision library (cv2)

import cv2
import os 
cwd = os.getcwd()
img=cv2.imread("test.png") ## this will get the 
cv2.imwrite('test_converted.jpg', img, [cv2.IMWRITE_JPEG_QUALITY,50])
OpenCV convertion demo
OpenCV convertion demo

side by side results

I also tried with image magic by following this tutorial:

https://jeuler.medium.com/how-to-convert-png-to-jpg-on-macos-using-imagemagick-9f85decc8678

where I got the following commands. The one to iterate over several files did not work for me.


cd Documents/Fab_Academy/images/week02
magick image.png output.jpg # for one image 
sudo for i in *.png; do convert “$i” “${i%.*}.jpg”; done  # for several but this did not work for me for some reason

I will use the previous png file that I used in the open cv demonstration to convert it to a jpg.

Imagemagick convertion demo
Imagemagick convertion demo

Finally, to decrease the size of videos of mp4 files we can use Quicktime by lowering the resolution.

Quicktime convertion
Quicktime convertion

Some advantages of using mp4 files are:

My global evaluator suggested to try ffmpeg, I installed it following this page

https://fabacademy.org/2025/labs/kannai/instruction/tips/macos_screenshots/#applescript_application


brew install ffmpeg

This program has many functions for video and audio editing. Some of their functions can be found:

https://www.vdocipher.com/blog/how-to-use-ffmpeg/

I used it to reduce a video file size. Using the following command


ffmpeg -i  Machining.mp4 -vf scale=1280:720 output.mp4
Quicktime convertion
Quicktime convertion
ffmpeg conversion
ffmpeg conversion

You can see that the size of the output file is almost half as the original one (Machining)

Assigment Files

Blender File

Gimp File

Inskape File

Fusion File

Reflection

I never had seen the concepts of objects and paths, and I would like to investigate this a bit more in the future.

=> I asked chat gpt: I would like to know what are object,paths and strokes in gymp vs. inskape

In GIMP and Inkscape, the terms objects, paths, and strokes are important concepts, but they are used in different contexts based on the software’s purpose.

GIMP (GNU Image Manipulation Program)

GIMP is primarily a raster graphics editor, which means it works with pixel-based images (like photos). However, GIMP does have some vector-like functionality as well.

  1. Objects:
    • In GIMP, “objects” are typically used to refer to layers or items within a composition (e.g., text, images, shapes). Objects are not the same as in vector software because GIMP works mainly with raster data.
    • GIMP layers can be seen as “objects,” and you can manipulate them independently, including moving, resizing, or editing their content.
  2. Paths:
    • Paths in GIMP are vector-based objects that allow you to create shapes or lines that are not pixel-based. Paths are often used for creating selections, guiding strokes, or as outlines for shapes that can later be filled or stroked.
    • Paths are editable and scalable without losing quality since they are not bound to pixels like raster images.
  3. Strokes:
    • In GIMP, strokes are used to apply a line (outline) to a path or shape. You can customize the stroke by setting its width, color, and style (e.g., dashed or solid).
    • A stroke is applied to a path, which makes it visible as a line, and it can be used for design or outlining shapes.

Inkscape

Inkscape is a vector graphics editor, which means it deals with objects that are defined using mathematical equations rather than pixels.

  1. Objects:
    • In Inkscape, objects refer to individual vector elements such as paths, shapes (like rectangles, circles), text, or images. These objects can be manipulated independently, including moving, resizing, rotating, and applying various effects.
    • In Inkscape, objects can be stacked in layers or grouped, and you can interact with each separately.
  2. Paths:
    • Paths in Inkscape are the fundamental building blocks of vector graphics. A path is a line or shape that consists of points (called nodes) and curves (Bezier curves).
    • You can manipulate these paths to create complex shapes, drawings, or lines. Unlike GIMP, where paths are more like selections or guides, in Inkscape, paths are the main form of drawing and illustration.
    • Paths in Inkscape can be open (like a line) or closed (like a shape).
  3. Strokes:
    • Strokes in Inkscape refer to the outline or border applied to a path, shape, or object. You can customize the color, width, and style of the stroke (solid, dashed, etc.).
    • Since Inkscape is vector-based, strokes are scalable, meaning you can resize them without losing quality.

Summary of Differences:

  • GIMP is a raster editor, so the main objects are layers (which can contain raster images, text, paths, etc.). Paths are used to create vector shapes and selections, and strokes are applied to these paths.
  • Inkscape is a vector editor, so objects are vector shapes, text, and paths. Paths are the core of the design, and strokes are applied to these paths or shapes.

In summary, paths in Inkscape are core elements for creating shapes, whereas in GIMP, paths are used more for selection and creating vector outlines. Strokes in both programs are outlines, but in GIMP, strokes are applied more to paths or selections, while in Inkscape, strokes are used for defining the appearance of vector shapes and paths.