20230524 ​

3D data

not use - can be represented in 2D form.

Exercises ​

What is a vertex ? ​

In mathematics, a vertex is a point where two or more lines, curves, or edges meet. In geometry, it is the common endpoint where two or more line segments, rays, or lines come together. In the context of a graph, a vertex is a point that represents a single entity, typically represented as a circle or dot, and can be connected to other vertices by one or more edges to form a network. The number of vertices in a graph can vary from a few to millions, depending on the complexity of the network.

What is the difference between a mesh, and a point cloud ? ​

A mesh and a point cloud are two different types of representations for 3D models.

A mesh is a collection of connected polygons that form the surface of an object. The polygons are usually triangles or quadrilaterals. Meshes provide a more detailed representation of the object's surface, as they can show details such as curves, edges, and textures. Meshes are commonly used in computer graphics, video games, and 3D printing.

On the other hand, a point cloud is a set of data points that represent the surface of an object. Each point in the cloud represents a single location in 3D space, and may have additional attributes such as color or intensity. Point clouds provide a less detailed representation of the object's surface compared to meshes, but are often used in applications where accuracy and precision are important, such as 3D scanning and LiDAR mapping.

In summary, while both meshes and point clouds are used to represent 3D objects, meshes offer a more detailed representation of the object's surface, while point clouds offer greater accuracy and precision in representing the object's geometric characteristics.

What is the difference between the types of data used in q.2. ​

The types of data used to represent meshes and point clouds are different.

A mesh is typically represented using a polygonal mesh data structure, which consists of a collection of vertices, edges, and faces. Each face in the mesh represents a polygon that forms a part of the object's surface. The vertices and edges define the shape of the polygons and provide connectivity information between them. Additional data such as material properties, texture coordinates, and lighting information can also be associated with the vertices and/or faces of the mesh.

In contrast, a point cloud is simply a set of points in 3D space, each defined by its position coordinates (x, y, z) and potentially additional attributes such as color, intensity, or reflectance. Point clouds can be stored in various formats, including ASCII text, binary, and specialized file formats such as LAS and PLY.

Overall, while both meshes and point clouds represent 3D objects, they differ in terms of their internal data structure and the type of information they store. Meshes use a polygonal data structure and represent surface geometry and associated properties, while point clouds consist solely of discrete points in space and may contain additional attributes describing the object's appearance or physical properties.

What is the main data structure used in Volume data visualisations ? ​

The main data structure used in Volume data visualisations are multidimensional arrays of scalar or vector data. These data are typically defined on lattice structures representing values sampled in 3-D space.

The main data structure used in volume data visualisation is the 3D grid or voxel grid.

In a voxel grid, the 3D space of the object being visualised is divided into small cubes called voxels. Each voxel represents a small portion of the object's volume and contains information about its properties, such as density, color, temperature, or other physical attributes. The values associated with each voxel are often represented as scalar or vector fields, which can be visualised using techniques such as volume rendering.

Voxel grids are a natural data structure for representing objects that have a well-defined volume, such as medical images, scientific simulations, or engineering models. They allow for efficient storage and processing of large amounts of volume data, as well as flexible manipulation and visualisation of the data in 3D space.

Overall, the use of voxel grids has become popular in many applications of volume data visualisation due to their ability to represent complex structures with high accuracy and detail, while also providing a standardised data format for interoperability and compatibility across different software platforms and hardware devices.

Which type of big data is held within the given data structure mentioned in above question ? ​

The type of big data that is held within the 3D grid or voxel grid data structure used in volume data visualisation is volumetric data.

Volumetric data refers to large datasets that represent the internal structure and properties of objects in 3D space, typically captured using imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound. Volumetric data can also be generated from simulations or other numerical models that simulate physical or biological processes in three dimensions.

Due to their high resolution and complexity, volumetric data sets can be very large and require specialised storage and processing capabilities. The use of voxel grids as a data structure allows for efficient representation and manipulation of volumetric data, enabling researchers, engineers, and other users to analyse and visualise complex structures and phenomena in 3D space.

Overall, the use of voxel grids and other techniques for handling volumetric data has become increasingly important in many domains, including medical imaging, materials science, geology, and fluid dynamics, among others.

List the advantages and disadvantages of 3D visualisations. ​

Advantages of 3D Visualisations:

1. Improved Understanding: 3D visualisations provide a better understanding of the object or project, making it easier for stakeholders to comprehend the design concept.

2. Effective communication: 3D models help communicate complex ideas more effectively between designers, engineers, and stakeholders. It allows everyone involved in the project to visualize the final product, making it easier to discuss and identify flaws or improvements needed.

3. Cost-effective: In many cases, using 3D visualization can be a cost-effective alternative to building physical models during the development phase. This helps to reduce the overall cost of the project.

4. Time-saving: With 3D visualization tools, designers can quickly create new designs and make changes without having to start from scratch. This saves time and resources.

5. Customization: 3D visualizations allow designers to customize objects or projects according to their preferences. They can adjust colors, textures, and lighting to achieve the desired visual effect.

Disadvantages of 3D Visualisations:

1. Expensive equipment and software: The cost of equipment and software required for 3D visualization is relatively expensive, which can be prohibitive for some companies or individuals.

2. Lack of realism: Despite its advantages, 3D visualization still lacks the realism of physical models or real-life objects. Some details may not appear as they would in the real world.

3. Technical skills required: Creating 3D models requires technical knowledge and skills that may be beyond the capabilities of some designers or engineers. This can lead to additional costs or delays due to the need for training or hiring specialized personnel.

4. Limited perspectives: Depending on the type of 3D visualization used, it may be difficult to view the design from all angles or perspectives. This can limit the ability to identify potential issues or improvements.

5. Hardware limitations: The use of 3D visualization requires powerful hardware to ensure smooth rendering and a high-quality output. This can be a challenge for individuals or companies with limited resources.

Define the word 'interactive'. ​

The word 'interactive' refers to something that is capable of acting or working together with a person, system, or other entity in a two-way or multi-way communication or exchange. It implies a reciprocal relationship where there is a response or feedback involved between the parties, resulting in an outcome that is affected by both parties. Interactivity can be found in various fields such as software design, gaming, education, and media, among others, where it is used to engage users or audiences for better participation and engagement.

When should you use 3D visualisations ? Give an example. ​

3D visualizations can be used in various applications, such as architecture, engineering, product design, and video games. Here are a few examples of when 3D visualisations can be beneficial:

1. Architecture: Architects use 3D visualisations to create a realistic representation of the proposed building or interior design. This helps them to communicate their ideas effectively with clients, stakeholders, and builders.

2. Engineering: Engineers can use 3D visualisations to simulate complex designs and test them under different conditions. This allows them to identify potential problems and make necessary adjustments before manufacturing.

3. Product Design: 3D visualisations can help product designers to create prototypes and visualize how the final product will look like. It also enables them to make changes quickly and efficiently during the design process.

4. Video Games: Video game developers use 3D visualisations to create immersive environments and characters that engage players. This enhances the gaming experience by providing a more interactive and realistic world.

For example, an architect may use 3D visualisations to create a virtual model of a building for a client to see what it would look like from all angles, both inside and out. This allows the client to get a better understanding of the design and make any necessary changes before construction begins.

When should you avoid 3D visualisations ? Give an example. ​

While 3D visualisations can be immensely beneficial in many situations, there are instances where they may not be necessary or even detrimental. Here are a few examples of when it might be best to avoid 3D visualisations:

1. Simple Designs: For simple designs, such as basic prototypes or low-cost products, creating a 3D visualisation may not be practical or cost-effective.

2. Limited Resources: In cases where resources are limited, such as small-scale projects or those with strict deadlines, the time and resources required to create 3D visualizations may not be justifiable.

3. Confidentiality Concerns: If confidentiality is a concern, such as for classified military projects or confidential product designs, sharing 3D visualisations may present a security risk.

4. Audience Preferences: In some cases, audiences may prefer other forms of media over 3D visualisations. For example, older customers may prefer traditional printed materials over digital ones.

An example of a situation where 3D visualization might be avoided would be for a small-scale project where the design is straightforward, and a 3D model is not necessary, this could include simple packaging design, flyers or posters that don't require much detail. In these cases, a 2D illustration or graphic could suffice and be more practical and cost-effective.

https://www.kaggle.com/code/dhanishahahaha/3d-visualisations/notebook

20230531 ​

GOMS GUI

keystroke-level model