direct volume rendering w/shading via three- dimensional textures

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.)