Object rendering
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This document discusses techniques for rendering 3D objects in computer graphics, including illumination models, shading models, and other effects. It describes different types of light modeling like diffuse and specular illumination. Common illumination models involve ambient, diffuse, and specular reflection. Shading models covered include flat shading, polygon mesh shading, Gouraud shading, and Phong shading. Other topics explained are transparency effects, shadows, and using textures to represent objects.
Object rendering
- 1. OBJECT RENDERING COMPUTER GRAPHICS UNIT VI -BY MS. ARTI GAVAS
- 2. INTRODUCTION • The objective of this chapter is ▫ To understand light modeling techniques and illumination models. ▫ To understand different types of shading models. ▫ To understand concepts Ray Tracing and Radiosity. An illumination model is used to calculate the intensity of light that we are going to see at a given point on the surface of an object. Illumination models are also some time called as lighting or shading models.
- 3. LIGHT MODELING TECHNIQUES • The object may be illuminated by light which can come from all direction. • A surface that is not exposed directly to a light source will be still visible if nearby objects are illuminated. • In basic illumination model we can set a general level of brightness of a scene. The method by which we create such effect usually follows the laws of reflections.
- 4. LIGHT MODELING TECHNIQUES • Two types: ▫ Diffused illumination ▫ Specular illumination light incident on each object is constant for all the surfaces and for all the direction. When the illumination is uniform from all directions it is called ‘diffused illumination’. Usually diffused illumination is a back ground light which is reflected from walls scenes and curve ceiling, floor. When we illuminate a shiny surface such as polish metal we observe highlight or bright spot on the shining surface. This phenomenon of reflection of light in concentrated area around the reflection angle is called specular reflection. Due to specular reflection the surface appears to be not in its original color but white, the color of the incident light.
- 5. ILLUMINATION MODEL • An illumination or lighting model is a model or technique for determining the colour of a surface of an object at a given point. • A simple illumination model can be based on three components: ▫ ambient reflection, ▫ diffuse reflection and ▫ specular reflection
- 7. SHADING • A shading model is used in computer graphics to simulate the effects of light shining on a surface. The intensity that we see on a surface is dependent upon two things one the type of light sources and second the surface characteristics: • Ex. Shining, matte, dull, and opaque or transparent. • Types: ▫ FLAT SHADING ▫ POLYGON MESH SHADING ▫ GAURAND SHADING MODEL ▫ PHONG SHADING
- 8. FLAT SHADING
- 9. FLAT SHADING
- 14. PHONG SHADING
- 15. PHONG SHADING
- 18. SHADOWS
- 19. TEXTURE AND OBJECT REPRESENTATION
- 20. TEXTURE AND OBJECT REPRESENTATION