Assignment 3

Ziwen Yuan

0

Transmittance Calculation

1.3

Grid Visualization
Rays Visualization

1.4

Sample Points

1.5

Volume Rendering
Depth Map

2.2

Box Center (rounded to nearest 1/100): (0.25, 0.25, 0.00) Box Side Lengths (rounded to nearest 1/100): (2.01, 1.50, 1.50)

2.3

Optimized Volume

3

NeRF

4.1

View Dependence
View dependence can capture specular details to show them with better realism, but risks overfitting to sparse training views, causing artifacts at novel viewpoints.

5

Sphere Tracing
Sphere tracing marches along rays by the SDF value at each point, iterating until the distance falls below a threshold or maximum steps are reached.

6

Input Point Cloud
Neural SDF
The MLP: fully connected layers with ReLU, with no final activation since SDF values can be negative. The eikonal loss enforces ||d f(x)|| = 1, for a valid distance function.

7

VolSDF Geometry
VolSDF Color
I used moderate beta (0.1) with increased eikonal weight to balance training stability and surface accuracy, providing strong gradients while maintaining geometric detail.

8.3

Alternate SDF to Density Geometry
Alternate SDF to Density Color
The NeuS naive approach uses density proportional to the SDF gradient's Laplacian, providing noisier gradients. VolSDF's sigmoid-based transformation offers smoother optimization.