Tech Art - Summer- Initial Overview of VFX Lecture Content

 

The topic of this lecture is stylized face shadow, with a focus on one practical application of SDF, or Signed Distance Field, in stylized rendering. The goal is not to create fully physically accurate lighting. Instead, I want the shadow on the character's face to respond to the light direction while still staying clean, stable, and readable. Realistic lighting usually follows geometry, material, and light behavior, but stylized face lighting cares more about a designed shadow shape. In other words, the shadow should feel closer to an illustration, instead of being completely controlled by small details on the model surface.

In the first part, I will briefly review basic Toon Shading and explain why it often fails on the face. Hard Threshold and Soft Threshold methods can create a clear light and shadow separation, but the face has many complex forms. Areas like the nose, eye socket, and cheek can easily create broken or unstable shadow shapes. For anime-style or illustration-style characters, this result is often not controllable enough and not very artist-friendly.

After that, I will compare several possible approaches, including Proxy Mesh Normals, Edited Topology and Normals, and a more direct Edited Normals workflow. These methods can all improve face lighting to some degree, but they have different costs in terms of control, maintenance, and visual stability. The main focus of the lecture will then move to SDF Shadow, because it allows us to separate the shadow shape from pure geometry-based lighting and let artists define a cleaner shadow boundary through texture.

The core idea of SDF is that each pixel stores more than a black or white mask value. It stores the distance to the nearest boundary, and also which side of the boundary the pixel is on. With this, a simple binary mask can become a continuous threshold map. Once this map is used in the shader, we can sample the Face SDF Shadow Threshold Map based on the light direction, so the shadow can transition between different directions while keeping the overall shape readable.

The final part of the lecture will explain how this texture is generated. The workflow starts by drawing binary masks for different shadow states, converting them into SDF maps, calculating intermediate transition textures, and then combining those transitions into the final threshold map used by the shader. This section is closer to the actual production workflow, and it also explains why the texture can record how the shadow shape changes over time or direction.

If time allows, I will also briefly introduce several ways to calculate SDF maps, including the most direct but slow Brute Force method, the more practical CPU-based 8SSEDT method, and JFA, which is more suitable for parallel processing on the GPU. Overall, this lecture starts from a visual target and follows the process through solution choice, shader usage, and texture generation, showing the Tech Art workflow behind a stylized rendering effect.

Common Art - Summer- Sprint #2

 

General

At the beginning of this sprint, we finalized the task distribution for the team.
My main responsibility on this cinematic project is to develop the water and waterfall systems.
I am also supporting Gabe S. by using Substance Designer to create several textures.
For this sprint, my primary focus is still the water work.
Since I was sick last week, I have been working hard this week to catch up with the schedule. At this point, I have completed the first version of the water shader/system.

Meetings and Documentation

At the beginning of this week, all of the Tech Art and 3D Art team members had a longer meeting to define the overall art style for the project. As a technical artist, one of my responsibilities was to help gather environment-related artist references.

Water

Since I am responsible for the water, I looked for several useful tutorials and breakdowns before starting development.
The most interesting reference I found was this one:
Stylized Water in UE5 Breakdown
This artist shared several techniques on X for creating stylized water in Unreal Engine.
His breakdown was very helpful for me.
He mentioned that he learned a lot from the following video, and I did as well:
How scrolling textures gave Super Mario Galaxy 2 its charm
This video explains many old-school water techniques used in Super Mario Galaxy. Even though these techniques are older, they are still valuable references today.
I recreated some of these ideas in Unreal. The current implementation is still simple, but after further refinement, some of these techniques should be useful for version 2 of my water system.

Because of the limited time for this version, my main goal was to establish the foundation and complete the basic rendering result.
The features and textures currently completed are:

Refraction and reflection effects 
Adjustable shallow/deep water control 
WPO waves + recalculated normals 
Stylized shoreline wave effect 
Water normal texture creation 
Foam noise texture creation 

The current water effect is partially compatible with Unreal's Water plugin. However, since the final environment will be built around an island, Unreal's official Water plugin may not always be the most convenient solution for our needs. Because of that, I implemented the wave motion using World Position Offset.
For the Gerstner wave implementation, I referenced this article.
Although the article is written for Unity, the logic can still be adapted to Unreal as long as the coordinate system differences are handled correctly. Unreal and Unity are both left-handed coordinate systems, but Unreal is Z-up while Unity is Y-up.

In the next version, I plan to start exploring:

Caustics effect
Sparkle/highlight effect
More stylized parameter controls

The goal is to push the water further toward a more stylized and cartoony look.

P4V

Common Art - Summer- Sprint #1

 VFX

There were not many tasks assigned to the Technical Artists during this sprint. My first task was to make sure the VFX created last semester could run reliably in our project. I organized and moved the VFX into the project, simplified the exposed parameters, and improved the adjustment workflow so that all artists can quickly use the effect.

Master Materials

In addition, Raghavendra and I were responsible for creating the Master Materials. The basic Master Materials have now all been integrated into the project.

Emissive Breathing

After finishing the basic setup, I also worked on a special technical art experiment. I created a GPU-based timer that does not rely on CPU control, which makes it very performance-friendly, and integrated it into the emissive material. This allows artists to freely adjust the emissive breathing effect, including customizing the glow duration and the interval between glow cycles.

Common Art - Spring - Lighting Workshop Module 3

 Final

Ref

Analysis + Creative process

My creative intent for this piece is actually not to make a heavily stylized environment. Instead, I want to create a natural, fresh atmosphere with a subtle sense of Chinese philosophy. For this “Lost Temple” scene, I’m aiming for an early-morning sunrise in a mountain ruin, when the mist hasn’t fully lifted yet. The fog won’t be exaggerated or overly stylized—I just want to convey a calm, everyday morning in a forgotten temple.

In the first image, I placed the entrance of the lost temple. Its worn-down, decayed state suggests that it’s an ancient place with no people around. The overall environment is relatively dark, but the brightness at the entrance is meant to draw the viewer’s attention—my goal is to guide the audience into the world of the scene through this inviting focal point.

In the second image, you can see a strong backlit setup. This is meant to communicate the time of day and the overall lighting condition of the environment. The third image reinforces what the first two are establishing: the ruined atmosphere and the sunrise timing.

The fourth image is the core shot. You can see that I didn’t add an overly dramatic top light to “glorify” the Buddha, because this is a damaged, weathered statue. I also don’t want the scene to feel overly artistic or theatrical. What I want to express is a sense of quiet plainness—despite the decay, the Buddha returns to simplicity and blends into the everyday world.

That said, I still tried to suggest a sense of sacredness, even if it’s subtle (because I don’t want it to be too exaggerated). I added a warmer rim light on the Buddha, and compositionally I framed the statue from the right looking toward the left. So in the lighting, I made a small deliberate choice: cooler light on the left side and warmer light on the right side, to hint at a gentle, warm radiance.

You can also see that I added fog to the environment. Unreal’s built-in fog effects couldn’t achieve the kind of sunrise atmosphere I wanted—where the mist hasn’t fully lifted yet—so I implemented my own volumetric fog to create that mood.

Tech Art - Spring - HW4 - Matrix Rendering Transformations

 

Assignment contents: 

Implementation Logic:

For this assignment, although my previous homework provided a solid foundation, I still refactored my Matrix4x4 / Vector4 math system to make it cleaner and more complete for this mini-renderer. This includes matrix multiplication, matrix–vector multiplication, transpose, and the w-component convention to distinguish points vs. directions. On top of that, I built the full pipeline for TRS, View, Projection, and the mapping from Clip/NDC space to pixel coordinates. To validate the implementation, I created two tests (Test and Test_Advanced) and then visualized the final result.

Test (Direct verification using the assignment parameters)

In the first test, I strictly used the parameters provided by the assignment to construct and print:

• World (TRS): W = T * R * S, with rotation composed as R = Rz * Ry * Rx

• View: V = R^T * T(-C) (the inverse of the camera’s world transform)

• Projection: both the Orthographic and Perspective projection matrices

• Final: MVP = P * V * W

Then, for the 8 vertices of the unit cube, I applied the full chain:
clip = MVP * local_point
ndc = clip / w
screen/pixel mapping
and printed each vertex’s local / clip / ndc / pixel values for inspection.

Test_Advanced (A more standard approach with a Camera class)

After the first test worked, I implemented an additional Camera class to better match a standard graphics pipeline structure. This class encapsulates camera parameters and generates the corresponding matrices (especially V and P, along with resolution/frustum-related setup). In Test_Advanced, I regenerated V and P through the Camera class and combined them with the same W to form:
MVP = P * V * W

I then repeated the same vertex transformation and pixel mapping process to ensure both approaches produced consistent results.

Visualization (matplotlib is only used for drawing)

To present the final result, I used matplotlib to draw the points and edges after they were projected into pixel space (scatter/plot for points and line segments, plus axis limits and grid display). Matplotlib is only used for rendering the lines/points— all computations (matrix construction, vertex transforms, perspective divide, and NDC-to-pixel mapping) are performed entirely by my own code. Matplotlib does not participate in any of the math; it simply visualizes the pixel coordinates I computed.

P4V:

I wrote the code in PyCharm. In the PyCharm project, I set up a virtual environment and installed the required libraries.

Tech Art - Spring - HW3 - Matrix Calculator 2

 

Assignment contents: 

Analysis:

This week’s tasks were fairly straightforward. The first part was to implement the matrix transformation that moves a model’s vertices from model space to world space. The second part was to build the interface for last week’s matrix calculator.

For Task 1, Nitin already explained the concept very clearly in class, so I won’t repeat it here. For Task 2, I tried to stay as faithful as possible to my previous UI design, but for practicality I also added an extra button under the Result section. It lets you copy the result matrix back into Matrix A, which makes chaining multiple operations much more convenient.

P4V:

Tech Art - Spring - HW2 - Matrix Calculator

Assignment contents: 

Analysis:

The code portion of this assignment is relatively straightforward—it's essentially an implementation of basic matrix calculations. My overall approach and structure are roughly as follows:

Core data structure: The matrix is stored as a 4×4 two-dimensional list in row-major order, which makes row/column access and arithmetic operations straightforward.

Construction & creation: There are two ways to create a matrix: if no data is provided, it defaults to a zero matrix; if a 4×4 set of rows is provided, the input is validated first and then all values are converted to floats to keep computations consistent. The class also provides static helpers like Zero, Identity, and FromRows to quickly generate common matrices.

Input validation: During construction, the code checks that the input is truly 4×4 and that every element is numeric, so errors are caught early and later operations don’t fail in confusing ways.

Display output: A formatted output function prints the matrix with a fixed number of decimal places and aligns columns by computing each column’s width, making the result easier to read.

Math features: The class implements essential matrix operations: addition, subtraction, scalar multiplication, matrix multiplication (using the standard row-by-column dot product rule), and transpose (swapping rows and columns). It supports both explicit method calls and operator-based usage for convenience.

Testing & verification: A simple test routine at the bottom of the file constructs example matrices and runs each feature in sequence to confirm the outputs and results behave as expected.

UI Design:

P4V: