Computer-Aided lIIustration
Computer-Aided lIIustration
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Illustration techniques in 3D CAD modelling are used to make designs look highly realistic and lifelike. Through rendering, effects such as shadows, lighting, textures, and reflections can be added to give the appearance of real materials and environments. This transforms a simple 3D model into something that looks like a finished product rather than just a digital sketch. By adding this sense of realism, rendering helps clients or employers clearly see how the design would look and feel in real life, making presentations and projects far more professional and convincing.
Materials
Materials
In CAD modelling, materials can be applied to 3D models to show clients or customers what a product will look like once it is made. For example, you can use wood, metal, glass, plastic, or fabric finishes to surfaces so the design looks realistic and professional. Adding textures further enhances the appearance of these materials by revealing details such as grain, roughness, or patterns. This makes the material look less flat and more like its real-world version. Applying realistic materials and textures is especially useful in environmental or architectural design, where clients need to see how surfaces like brick, concrete, or water will look at the correct scale within the setting. This enhances realism and helps the viewer imagine the finished space accurately.
Texture Mapping
Texture Mapping
Texture mapping is the process of applying a 2D image (a texture map) onto a 3D model to give it realistic surface detail, such as wood grain, stone, glass, or metal. In an exam answer, it’s essential to focus on how texture mapping enables materials to appear correctly scaled within their environment. It is shown in plain colour and does not have any depth to it.For example, if you are modelling a building, texture mapping ensures that bricks, tiles, or windows are the right size compared to the overall structure. Without proper scaling, textures might appear stretched, repeated too often, or out of proportion, which would make the model look unrealistic. Advanced software can also generate textures directly onto a 3D object, allowing for seamless finishes. For instance, a sphere could be given a realistic wood grain that matches the proportions of the object without distortion.
Bump Mapping
Bump Mapping
Bump mapping is a technique used in computer graphics to make a surface look like it has bumps, dents, or wrinkles without actually changing the shape of the 3D object. It works by altering the way light reacts with the surface during rendering. The lighting calculations are adjusted so that shadows and highlights appear as if the surface is uneven. The result is a surface that looks textured and detailed (e.g. rough stone or wrinkled fabric), but the underlying model remains smooth.
Lighting
Lighting
Lighting in CAD modelling is used to make objects look more realistic and visually effective. Different lighting styles can change how bright, dull, or dramatic a model appears, and they are chosen depending on the effect or setting required. Ambient - Creates an overall, even level of light across the whole scene. It uses colour, temperature, and brightness to give a consistent glow, so there are no harsh shadows. This is useful for making environments look naturally lit and creates a positive ambience within the environment.
Spot - A strong, cone-shaped, focused beam of light directed onto a specific area or object. It is often used to highlight a product or display, drawing the viewer’s attention to one key feature. It is often used in scenes where a specific feature/character has to be emphasised.
Point - Placed at a single point in space, this type of light shines equally in all directions, similar to a bare light bulb. It creates natural highlights and shadows depending on the position of the light source. It can be used to create internal lights within scenes to ensure the type of lighting fits the styling/ interior of the design.
Area - Covers a wider or specific region, ideal for lighting large spaces or surfaces evenly. This type of lighting is commonly used in architectural design to represent how real spaces are lit.
Directional - Produces parallel light rays that all travel in one direction, similar to sunlight. Because the rays extend to infinity, it’s effective for creating outdoor daylight scenes or strong shadow effects. For example, it could be used to replicate directional sunlight coming through or casting daylight throughout scenes/environments.
Spot - A strong, cone-shaped, focused beam of light directed onto a specific area or object. It is often used to highlight a product or display, drawing the viewer’s attention to one key feature. It is often used in scenes where a specific feature/character has to be emphasised.
Point - Placed at a single point in space, this type of light shines equally in all directions, similar to a bare light bulb. It creates natural highlights and shadows depending on the position of the light source. It can be used to create internal lights within scenes to ensure the type of lighting fits the styling/ interior of the design.
Area - Covers a wider or specific region, ideal for lighting large spaces or surfaces evenly. This type of lighting is commonly used in architectural design to represent how real spaces are lit.
Directional - Produces parallel light rays that all travel in one direction, similar to sunlight. Because the rays extend to infinity, it’s effective for creating outdoor daylight scenes or strong shadow effects. For example, it could be used to replicate directional sunlight coming through or casting daylight throughout scenes/environments.
Volumetrics
Volumetrics
Volumetric lighting is a technique that makes light look like it is interacting with airborne particles in the environment, such as dust, smoke, fog, or mist. This gives the impression that light has depth and volume, rather than being invisible until it hits a surface. By including these particles in the lighting effect, designers can create much more realistic and atmospheric scenes. For example, sunlight streaming through a dusty room shows visible light rays, or headlights glowing in smoke appear to cut through the air. Volumetric lighting is also used to add realism to water features, where light passing through mist, spray, or waves helps show the depth and volume of the water.
High Dynamic Range Imaging (HDRI)
High Dynamic Range Imaging (HDRI)
High Dynamic Range Imaging (HDRI) is a technique used in digital graphics and photography to capture and reproduce a much wider range of brightness and contrast than standard cameras normally allow. The goal is to make images look closer to how the human eye sees the real world, where we can adjust to both very bright and very dark areas at the same time. Standard cameras without HDR can only capture a limited exposure range, which often means losing detail in highlights or shadows, for example, bright skies becoming pure white or dark areas turning completely black. HDRI solves this by combining multiple photos of the same scene taken at different exposures, merging them into one image that enhances the colour and shadow.
Specularity
Specularity
A Specular highlight is the bright spot of light that appears on shiny objects when illuminated.
These highlights are important in 3D computer graphics as they provide a strong visual cue for the shape of an object and its location with respect to light sources in the scene.
In computer graphics, it represents the amount of reflectivity a surface has. It is a key component in determining the brightness of specular highlights, along with the shininess, to determine the size of the highlights.
These highlights are important in 3D computer graphics as they provide a strong visual cue for the shape of an object and its location with respect to light sources in the scene.
In computer graphics, it represents the amount of reflectivity a surface has. It is a key component in determining the brightness of specular highlights, along with the shininess, to determine the size of the highlights.
Sited Environment
Sited Environment
When a model has been created, the designer can place the model into an environment.
This allows the model to appear in realistic surroundings.
It is used to show:
This allows the model to appear in realistic surroundings.
It is used to show:
- Models in a realistic setting
- The model with additional features like trees, roads, cars etc.
- Gives a clearer idea of scale
- Can show different conditions like how it would look in light, dark or sunny conditions
Depth of Field
Depth of Field
Depth of Field is the distance between the closest and farthest objects in an image that still look sharp and in focus. A camera lens can only focus perfectly on one point at a time, so everything in front of or behind that point gradually becomes less sharp. Depth of Field can be adjusted to change the look and feel of a scene:
- A large depth of field keeps most or all of the image in focus. This is useful for landscapes, architectural designs, or technical images where all details need to be clear.
- A small depth of field keeps only part of the image sharp (such as the subject), while the background and foreground are blurred. This draws attention to the main subject and creates a more dramatic or artistic effect.
Image Based Lighting (IBL)
Image Based Lighting (IBL)
Image-Based Lighting (IBL) is a 3D rendering technique that uses real-world lighting information to make digital scenes look more realistic. A special camera captures a 360° high dynamic range image of an environment, which records the colours, brightness, and direction of light. This image is then projected onto a sphere (like environment mapping) and used to light the 3D objects inside the scene. The key idea is that IBL simulates how the surrounding environment affects the lighting of objects. For example, if a 3D model is placed in a captured street scene, the reflections and shadows on the object will match the light coming from that real location.
Basic Steps of IBL:
- Capture real-world illumination as a 360° HDR image.
- Map the illumination onto a digital sphere representing the environment.
- Place the 3D object inside the virtual environment.
- Simulate how the light from the environment interacts with the object.
Polygon Modelling
Polygon Modelling
In 3D computer graphics, polygonal modelling is a method of creating objects using polygon meshes: networks of connected flat shapes (usually triangles or quads). Each polygon is defined by its vertices (points) and edges (lines joining them). By combining many polygons, designers can build detailed 3D models of almost any shape. Increasing the number of polygons makes the model smoother and more realistic (high-poly), while fewer polygons are used for simpler, faster models (low-poly). Designers use Boolean functions to edit shapes:
- Add: joins two shapes together.
- Subtract: removes one shape from another.
- Intersect: keeps only the overlapping area.
- Slice: used to cut through a model to view or edit its internal structure.
Boolean Functions
Examples
Examples
Illustration and lighting techniques are used in the production of animated movies and video games such as those shown.
a. Describe eight illustrations and/or lighting techniques that can be used to add realism to animated movies or video games.
a. Describe eight illustrations and/or lighting techniques that can be used to add realism to animated movies or video games.
Answer (8 of the following)Materials could be applied to enhance the realism of environment designs Texture mapping would allow materials to be scaled correctly within environments to ensure they worked with the size of items such as buildings etc within the setting Bump mapping could be used to enhance materials/character costumes/surfaces to add more texture using rough/variable/ irregular surfaces Reflection could be added for realism by reflecting the scene or individual elements within the environment Specularity and additional highlights added to gloss/metallic/reflective surfaces to enhance reflective material and/or emphasise direction of lightingSpecularity may appear as rings of light/lens flair for a unique effectAmbience mood/feeling produced by light/colour schemes to create a positive ambience within the environment Volumetrics and the inclusion of air-born particles (for example dust/smoke etc) within an environment Volumetrics could be used to create added realism to water features showing the depth and volume of these featuresDirectional Lighting could be used to replicate directional sunlight coming through or casting daylight throughout sceneAmbient light could be used to produce an overall light with no specific direction to ensure all areas have general illumination Spotlight could be used in scenes where a specific feature/character has to be emphasised Area Light could be used to create internal lights within scenes to ensure the type of lighting fits the styling/ interior of the design Point Light could be used to create internal lights within scenes to ensure the type of lighting fits the styling/ interior of the design Image Based Lighting could be used to simulate how the surrounding environment effects the lighting of objectsImage Based Lighting could mean images/lighting of real-life environments can be translated to the movie/game to ensure the lighting within the environment is as accurate as possible HDRI will ensure the range of shade/ luminosity is accurate to how real/natural lighting would affect darker/lighter areas or adjustment of light within scenes or environments
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