3D Materials and Texturing Techniques

Materials

• Materials define the appearance and substance of a mesh, including color, texture, reflection to light, and how light interacts with the object
• Materials are data blocks that can be assigned to multiple 3D objects
• Materials can be assigned to different parts of a single 3D object
• Materials consist of three shaders: Surface, Volume, and Displacement

Surface Shader

• Controls textures and light interaction on the surface of the mesh
• Can include reflection, transmission, and refraction
• Refraction is adjusted through IOR with a default value of 1.45

Volume Shader

• Defines the interior of the mesh
• Mostly used for creating fire and smoke or combined with the surface shader for a halo texture
• Principled Volume is a physically-based volume shader that can be used for a wide range of volume materials

Texturing

• Texture is the base colour of materials
• Understanding texturing requires knowledge of adding materials to an object
• Texture affects the surface of an object, while materials affect the entire object

Types of Texture

• Procedural:

  • Uses nodes to manipulate texture mathematically
  • Resolution independent
  • Doesn't depend on an image

• Bitmap:

  • Image texture or texture painting
  • Requires UV mapping
  • Achieves realistic materials quickly
  • Can be used with JPEG, PNG, and TGA file formats

UV Editing

• UV Editing workspace controls and manipulates 2D forms of the mesh and how textures are applied
• UV editing can improve UV mapping by adding seams and rearranging UVs to minimize overlapping

Displacement

• Alters the shape of a surface or volume, creating more detail
• Can be achieved through Procedural, Paint, or Baked textures
• Displacement is the most accurate but memory-intensive method, requiring finely subdivided meshes
• Bump Mapping provides visual alteration to shading but not the actual mesh
• Mixed displacement uses actual displacement for larger details and bump mapping for finer details

Blender Render Engines

• Blender has several render engines
  • Workbench: Used for rendering during modeling and testing animations
  • Cycles: Internal Blender engine, known for producing high-quality scenes
  • Eevee: Short for Extra Easy Virtual Engine, provides faster rendering power

Shading Nodes

• Shading nodes are input values that produce a material
• The Principled BSDF is the default node, combining multiple layers into a single easy-to-use node, also known as the "Uber" Shader
• Additional shading nodes include:
  • Principled Hair BSDF: Ideal for rendering hair and fur
  • Principled Volume: Combines all volume shading components into one node
  • Refraction BSDF: Adds glossy refraction with sharp or microfacet distribution
  • Specular BSDF: Combines multiple layers into a single node
  • Anisotropic BSDF: Adds glossy reflection with separate control over roughness in U and V directions
  • Toon BSDF: Creates diffuse and glossy materials with cartoon light effects
  • Diffuse BSDF: Adds Lambertian reflection with lower roughness (standard is 0.0) and Oren-Nayar reflection (with higher roughness values)
  • Transparent BSDF: Adds transparency without refraction, passing straight through the surface
  • Translucent BSDF: Adds Lambertian diffuse transmission
  • Velvet BSDF: Adds reflection to materials like cloth
  • Volume Absorption: Allows light to be absorbed as it passes through a volume
  • Volume Scattering: Allows light to be scattered as it passes through a volume
  • Emission: Adds a Lambertian emission shader
  • Glass BSDF: Creates a glass-like shader that blends refraction and reflection at grazing angles
  • Glossy BSDF: Adds reflection with microfacet distribution, perfect for materials like metal or mirrors
  • Hair BSDF: Adds shading for hair
  • Holdout: Creates a "hole" in the image with zero alpha transparency, useful for compositing
  • Mix Shader Node and Add Shader Node: Both achieve similar results but Mix shader assigns the dominant shade between two shades using FAC.

Curves

• Curves are composed of Splines which are the individual elements of the curve
• Types of Splines:
  • Poly Spline: The simplest type of spline with no interpolation
  • Bézier: Use control points and handles to define shape and curvature
  • NURBS: Use mathematical form for generating and representing curves and surfaces

Editing Splines and Curves

• Toggle Cyclic: Switches between open and closed curves
• Set Spline Type: Converts splines between Bézier. NURBS, and Poly curves
• Decimate Curve: Reduces the number of control points while maintaining the initial shape
• Control Points: Allow for editing and managing control points, including extruding, creating segments, tilting, smoothing curves
• Segments:
  • Subdivide: Adds control points between segments
  • Switch Direction: Reverses the direction of a curve

Properties of Shape Panel

• Resolution Preview/Render U: Sets the number of points computed between control points
• Twist Method: Allows control of control points not located on the curve's local XY plane
• Transform Tool: Allows editing Bézier curves by transforming control points and handles. NURBS curves have only control points
• Smooth: Smooths the curve, removing twists
• Fill Mode: Determines how a curve is displayed when beveled
  • Fill Deformed: Fills the curve after applying modifications
  • Radius: Scales the deformed object by the set curve radius
  • Stretch: Stretches or squeezes a mesh object along the curve
  • Bounds Clamp: Ignores object/mesh offset along the deformation axis, useful with the Stretch option or negative axis

This quiz covers the fundamentals of materials and texturing in 3D modeling. It explores the different shaders, including Surface and Volume shaders, and their roles in defining material properties. Test your understanding of how materials affect the appearance and behavior of 3D objects.