Final Project Report – Deheng Zhang & Ganlin Zhang

Motivational Image: "Christmas on the Moon"

Three robots, Cat on the moon, Christmas

The idea of this image is to have a Christmas party on the moon. The three robots and cat on the moon images are from the Netfilx television series Love Death + Robots . The story is about long after the fall of humanity, three robots embark on a sightseeing tour of a post-apocalyptic city. And the cats occupies the moon as their homeland. The third image is from the Nintendo game Animal Crossing: New Horizons, which shows a Christmas party scene.

The idea behinds our project proposal is to generate a similar scene as in the motivational images, we do not intend to reproduce the images exactly, but want to combine these scenes: Some robots and creatures are on the moon for Christmas party, and there is an earth (flooded by lava) on the background. We assume that the Moon will snow in the future and that ice exists. Vegetation is also present. We also want to create chimneys with smokes coming out. These scenes may show a few interesting phenomena for rendering, e.g. different matrial of surface, glossy reflections, homogeneous medium, emissive texture etc.

Features to implement:

Here is our proposed feature list we would like to implement. After the list we describe why we want to implement this feature and what for it is used for in the final image.

Deheng Zhang

Following features are summing up to 60 points.

5 Points
- Basic Denoising: Bilateral Filter with Uniform Variance
- Simple Extra Emitters: directional light
- Anisotropic Phase Function (e.g. Henyey-Greenstein)
- Object Instancing
10 Points
- Different distance sampling and transmittance estimation methods: ray marching, delta tracking and ratio tracking
30 Points

Ganlin Zhang

Following features are summing up to 60 points.

5 Points
- Images as Textures
- Bump Mapping or Normal Mapping
- Simple Extra BSDF: Conductor
- Simple Extra BSDF: Blend BSDF
10 Points
- Stratified Sampling
15 Points
- Environment Map Emitter
- Disney BSDF (5 params: roughness, specular, metallic, sheen, sheen_tint)

Simple Extra Emitters: directional light

There are four emitters except the environment. Including the headlamps and warning light.

Validation: We will try to generate a valid xml-test file as it already exists for the point-light.

Images as Textures

This feature is needed for the painting of the police vehicle to make it looks more realistic.

Validation: The result of this feature would be easily checked whether it is correct or not by eyes.

Basic Denoising: Bilateral Filter with Uniform Variance

The denoising step is important to reduce noisy points in the rendered images. Baisc denoising would appplied in our project.

Validation: A simple scene would be rendered with and without the denoising technique, we will check the quality of these rendered images to see whether the denoising part is implemented correctly or not.

Bump Mapping or Normal Mapping

We want to simulate the fluctuating surface of the water, thus, bump mapping is needed.

Validation: The rendered scene will be visualized and be compared with the results of other reneders.

Simple Extra BSDF: Conductor

More BSDF is needed to simulate the texture of different surface like metal

Validation: The rendered objects will be visualized, a plot of BSDF of certain material is also possible.

Simple Extra BSDF: Blend BSDF

Blend BSDF will be used to mix multiple BSDF to better simulate object with complicated surface. i.e. surface of the Earth.

Validation: The rendered scene will be visualized and be compared with the results of other reneders.

Anisotropic Phase Function

The Henyey-Greenstein phase function is a very popular empirical phase function. We would like to implement this function for volumetric rendering.

Validation: We will compare the result of this phase function with the uniform phase function. Besides, we will test some hand-computed values or visualize the sampled directions to check the correctness.

Object Instancing

Since we use one model multiple times (e.g. the Christmas gifts), and shape groups (the Christmas pine with candies on it), we need to instantiate the object.

Validation: we will directly check whether the object is reused in the scene.

Different distance sampling and transmittance estimation methods

The different distance sampling is used for the volumetric rendering pipeline.

Validation: We will compare the sampling result with other render such as mitsuba.

Stratified Sampling

Stratified sampling can be used to reduce the aliasing effect.

Validation: We will try to visualize the sampled point in the warptest GUI.

Environment Map Emitter

This feature is to give a realistic background of our image. Also, the image we want to render does not contain much light source, so that it is also used for providing enough light for this scene.

Validation: Use some existing open-source renderers to render a same scene and check if the results are similar.

Disney BSDF (5 params: roughness, specular, metallic, sheen, sheen_tint)

More BSDF is needed to simulate the texture of different surface, i.e. metal, plastic, glass, etc. And Disney BSDF technique will be applied to simulate more realistic surfaces.