Weekly Assignments

week02 Computer-Aided Design

1.Model raster, vector
2. 2D Model
3.3D Model, render, animate, simulation.
4.a possible final project, compress your images and videos, and post a description with your design files on your class page
Learning outcomes
Evaluate and select 2D and 3D software
Demonstrate and describe processes used in modelling with 2D and 3D softwares
Demonstrate image and video compression
Have you answered these questions?
Modelled experimental objects/part of a possible project in 2D and 3D software
Shown how you did it with words/images/screenshots
Documented how you compressed your image and video files
Included your original design files

1.Model raster, vector

Raster

A raster is a digital representation of images formed by a rectangular grid of individual pixels or dots, where each pixel carries a specific color or intensity value. This structure allows for detailed image rendering by defining the color information at each point in the grid. Raster graphics are widely used in photography, digital art, printing, and screen displays because they can accurately capture complex color gradients and fine visual detail. However, since raster images are resolution-dependent, scaling them beyond their original size can result in pixelation or loss of quality, unlike vector graphics which remain crisp at any size.
Raster Image

Raster

A vector is a mathematical quantity that possesses both magnitude (size) and direction, making it essential in accurately describing physical phenomena. In physics and engineering, vectors are widely used to represent quantities such as force, velocity, acceleration, and displacement, where the direction of the action is just as important as its strength. Vectors are typically represented graphically by arrows, where the length corresponds to magnitude and the arrowhead shows direction. Unlike scalar quantities, which have only magnitude, vectors provide a more complete description of motion and forces, making them fundamental tools in analyzing and solving real-world engineering and physics problems.

Vector Image

Vector Image

2. 2D

Key points about FreeCAD:

FreeCAD is an open-source 3D CAD modeler focused on parametric design. Parametric modeling allows you to easily modify designs by changing parameters like dimensions. You can build complex models using sketches, constraints, and features like pads, pockets, and patterns. FreeCAD supports scripting with Python, making automation and customization powerful and flexible.
I download freecad 1.0 for my window P.c

I open freecad and select newfile and 2d draft.

then i select the tool for 2d rectangle.

i drag the rectangle in my freecad work area and mark the dimension required in the side box. then the rectangle is created in 2d vector file.we can generate any design and dimension based on our design in vector 2d.

3.3D Modelling, Rendering, animate, simulation.

I select Blender as Modelling tool Graphics software tool set that runs on Windows, macOS, BSD, Haiku, IRIX and Linux. It is used for creating animated films, visual effects, art, 3D-printed models, motion graphics, interactive 3D applications, and virtual reality. It is also used in creating video games.

I planned to create a 3D model of a dog using block-based modeling techniques in Blender 3D, a powerful open-source 3D creation tool. My goal was to design the dog using simple geometric shapes, primarily cubes and rectangular blocks, to give it a stylized, low-poly appearance. This approach makes it easier to model and manipulate each part of the dog—like the body, legs, head, and tail—while maintaining a clean and structured design. Working in Blender allowed me to understand basic modeling tools such as extrusion, scaling, and alignment, which are essential for building more complex 3D forms later.
I Plan a 3d model of Dog build by block in blender 3D

I started working in Blender to bring my design idea to life, based on what I had decided to create. After finalizing the concept, I began by setting up the basic layout and familiarizing myself with Blender’s interface and tools. This included using functions like object creation, scaling, and positioning to shape the initial blocks for my model. Starting with a clear plan made it easier to stay focused and follow a structured workflow. This hands-on experience helped me better understand 3D modeling techniques and gave me confidence in using Blender for future digital design and fabrication projects

I opened Blender 3.6 and was greeted with the default startup screen. From there, I selected the General option, which provided me with a basic workspace setup that includes a default cube, camera, and light. This is the standard starting point for most modeling projects in Blender. The General layout is ideal for beginners because it offers a clean environment with essential tools for 3D modeling, animation, and rendering. This screen marks the beginning of the creative process, where I can now start modifying objects, adding new shapes, and building the structure for the project I planned to create.

Once Blender opened and I selected the General workspace, a default square cube appeared in the center of the scene. In Object Mode, I selected the cube and used the scale tool to stretch it along the X-axis, giving it a rectangular shape. This helped form the base structure for my model. After adjusting the shape, I switched to Edit Mode to make more detailed changes. In Edit Mode, I selected the appropriate face or edge and used the subdivide tool specifically along the X-axis to create additional segments, which allowed for more precise editing and better control over the shape.

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After subdividing the cube along the X-axis in Edit Mode, I proceeded to further refine the geometry by applying subdivision along the Y-axis as well. This step added additional vertical segments to the model, allowing for more detailed manipulation of the shape. By creating a grid of smaller faces through subdivision in both X and Y directions, I gained greater flexibility in shaping the object’s surface. This is especially useful when modeling block-based designs, as it provides more control points for adjusting specific areas of the model and building a more defined, complex structure as the project progresses.

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After subdividing the cube along both the X-axis and Y-axis, I selected the four subdivided corners of the shape and used the extrude tool to pull them down. This action formed the four legs of the model, giving it a more defined structure. Next, I focused on the top front section of the cube. I selected the center division of the top face and extruded it upwards to create the neck. This step helped shape the body of the dog and establish its basic form. The extrusions allowed for easy manipulation and provided a foundation for further detailing

After forming the neck, I moved on to shaping the tail of the model. I selected the back center subdivision on the top rear face of the mesh in Edit Mode. Using the extrude tool, I pulled this section outward to form the tail of the dog. This extrusion gave the model a more complete and recognizable silhouette. By carefully adjusting the length and angle of the extrusion, I was able to create a simple, blocky tail that matched the overall low-poly style of the model. This step completed the basic structure of the dog using Blender’s modeling tool

To add more detail to the model, I selected the top face of the tail and used the extrude tool along the Y-axis to create a tail bend, giving it a more natural and dynamic look. This slight curve enhanced the overall shape while maintaining the blocky style. Then, I moved to the front of the neck, where I selected the appropriate face and extruded it along the Y-axis to form the head. This extrusion extended the geometry forward, creating the basic shape of the dog's head and completing the primary structure of the model in Blender.

To add more detail to the head of the model, I first subdivided the head section to create additional geometry for finer control. Then, I selected the two top corners of the head—one on each side—and used the extrude tool along the Z-axis to pull them upward, forming the ears of the dog. This step gave the model a more recognizable and expressive appearance while keeping the block-style aesthetic consistent. The extruded ears added character and depth to the model, making it look more complete and helping distinguish the head from the rest of the body.

Thus, I successfully completed my 3D model, designed entirely using basic block modeling techniques in Blender. The model represents a stylized dog, constructed by extruding and shaping a simple cube through a series of well-planned steps, including forming the body, legs, neck, tail, head, and ears. Each part was carefully adjusted to maintain a clean, low-poly appearance suitable for 3D printing. This project helped me understand essential modeling tools such as scaling, subdivision, extrusion, and axis control. With the final structure complete and properly proportioned, the model is now ready to be exported and prepared for the 3D printing process.

Rendering

Rendering is the process of converting a 3D scene into a 2D image, allowing the visual representation of the model to be finalized. It involves complex calculations of lighting, shadows, reflections, materials, and camera positioning to produce a realistic or stylized output. In Blender, there are two primary rendering engines: Cycles and Eevee. Cycles is a path-tracing engine known for its high-quality, photorealistic renders, ideal for final outputs. On the other hand, Eevee is a real-time render engine that provides faster previews and outputs, making it suitable for quick visualization and animations where speed is a priority.

Sampling

Sampling in rendering refers to the number of rays or calculations used per pixel to determine the final image quality. In Blender, especially when using the Cycles render engine, higher sampling means more accurate lighting, shadows, and material reflections, resulting in a cleaner and more realistic image. However, higher samples also increase render time. Lower sampling can speed up the process but may introduce noise or graininess in the image. Blender allows users to control the number of samples for both preview and final renders, enabling a balance between performance and quality depending on the needs of the project.

Render 300
For my final render, I set the sampling value to 300 in Blender using the Cycles render engine. This means that for each pixel in the image, Blender calculates the lighting and shading information using 300 samples, which helps produce a much cleaner and more detailed render with minimal noise. Choosing 300 samples strikes a good balance between image quality and render time, especially for still images where a more refined look is required. This setting allowed me to showcase my 3D model with improved lighting accuracy, shadows, and material definition, giving the final output a more polished appearance.

For the final appearance of my 3D model, I chose a black and white color scheme. This minimalistic approach gives the model a clean and bold aesthetic, emphasizing its blocky structure and geometric form without distraction from bright or complex colors. In Blender, I assigned a black material to the main body and used white for specific parts like the legs, ears, or tail to create contrast and highlight different sections. This simple palette not only aligns with the low-poly style but also ensures the model remains visually striking when rendered or prepared for 3D printing.

The final output of my project is a block-style 3D dog model, fully designed and rendered using Blender 3.6. The model features distinct body parts like legs, neck, tail, head, and ears—all shaped through subdivision and extrusion techniques. I used a black and white color scheme to give the model a clean and stylized look. The render was done using the Cycles engine with 300 samples to ensure clarity and reduced noise. This final result reflects my understanding of basic 3D modeling, rendering, and design aesthetics, and it’s now ready for presentation or 3D printing.

I tried text to 3d model zoo.dev

As part of my exploration into AI-assisted design tools, I tried using Zoo.dev, a platform that allows generating 3D models from text prompts. This tool uses advanced AI algorithms to interpret natural language input and convert it into a corresponding 3D object. I found it interesting because it simplifies the modeling process for beginners or for quick concept visualization. By simply describing the object I wanted, the platform generated a basic 3D shape that could be further refined or exported. It gave me a new perspective on how generative AI can assist in digital fabrication and rapid prototyping.