Direct Volume Rendering w/Shading via Three- Dimensional Textures

Introduction Intro Limitations Other methods

Overview of Texture-Map Initial step Lookup table computation Texture map processing

Ambient Light Calculation

Reflecting Surface Classification Calculation

Reflected Light Component Half-way vector specularity model Lambertian diffuse shading

Gradient Quantization Quantize gradient direction Unit Sphere Tessellation

Rendering Slices Apply texture Back to front ordering

Texture Coords Bounding cube Transformation:

Alternative Pipelines

Results

Footprint Evaluation for Volume Rendering

Introduction Forward-Mapping Algorithm Overview

Previous Work Ray tracing Compositing techniques Fitting surfaces into data cells

Rendering Algorithm Differences from original algorithm Algorithm breakdown  Transforming  Shading  Reconstruction  Visibility Splatting

Footprint Function Calculate once for each view

Generic Footprint Table Spherical Kernel Integration along the Z axis

Extents and Mapping Two cases

Extents and Mapping (cont.) Extent Mapping Ellipsoid defined as

Table Sizes and Kernels 3 Parameters  Size of the table Space vs. Quality tradeoff  Accessibility of the table  Table’s underlying kernel

Table Sizes and Kernels (cont.)

Sample Images

Sample Images (cont.)