HW 4: 3D Stylization Submission (Charles Wang)

showcase.mp4

1. Concept art

All three pieces are by OMOCAT and her team!

Piece 1	Piece 2	Piece 3

I wanted to recreate the art style of OMORI, a game that is unique for its colored pencil look and animated outlines/sprites the characters, world, and environment.

2. Interesting Shaders

I added multiple light support by following the tutorial.

Specular highlight

I didn't like how the specular highlight looked in my scene so I don't use it in the final setup, but here I show the implementation working (and it's available as a separate Shader Graph called "ToonWithSpecular" in the Shaders folder).

Recording.2024-11-03.002800.mp4

Interesting shadow

To emulate the scribble-y look of OMORI, I used the pencil brush from Procreate to create this 512x512 texture, and tiled it using the website:

Later on I also create a "lighter" version of the texture when I want the lines to be less sparse.

Special surface shader

To create the "selected" shader, I drew inspiration from two sources in the game. The first is how sometimes the art likes to invert colors. See this YouTube video and look at the bottom left corner, OMORI flips colors. Also this picture:

I also wished to animate the selected object using the drawn look as seen in the game, which I did by reusing the shadow texture and overlaying it on the object. I used time, a triangle wave, and floored it so I could get staggered values to use to rotate the UV coords, allowing me to "animate" it. Here's a pic of the Graphtoy I used to plan it:

For this shader, I also went back to the shadow and made it animated in the same manner, using a different offset/time scale so it looks different from the actual object.

3. Outlines

I first implemented basic outlines using the Roberts Cross method.

However, outlines in OMORI art seem to be made up of three parts: a green, pink, and purple piece all overlayed on each other.

So I do just that in my shader, blending between them using Darken. In addition, each of the three outlines are customized by slightly offsetting the UVs to give a more "chromatic aberration" look, and I use the Random Range node to vary the thickness of the outlines depending on screen position. Finally, I use the same animation technique that I used in the surface shader above. Final result:

4. Full Screen Post Process Effect

Inspired by the white border that surrounds the first concept art piece, I decided to implement a white-colored vignette that goes around the screen borders. (I use the vignette "value" later on for interactivity. More deets below.)

5. Create a Scene

Models and credits:

• "Picnic Basket from Poly by Google" (https://skfb.ly/6XXuR) by IronEqual is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
• "Low Poly Laptop" (https://skfb.ly/o9G6r) by zgoosr is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
• "Low Poly Picnic Asset Pack" (https://skfb.ly/6TtZR) by lizhiqiang is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
• "Door" (https://skfb.ly/opVZ9) by Arnau Rocher Alcayde is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).

For the laptop, I created a custom shader that specifically draws a texture to the screen geometry. To prevent the door from self-shadowing (and looking uglier), I added a UseShadow parameter that completely turns off shadow attenuation in the main toon shader. (We're not exactly being realistic in this HW.)

Moving background

I wanted to include a background from the game as my scene's background. As a hack, I positioned a plane as a child of the main camera and created a shader that translated over the UVs of the background image as a texture, which is sampled using the UVs. This is then the final fragment output. I use this shader in a material that I put on the plane. Now the plane rotates along with the camera, so it looks like a background overlay!

6. Interactivity

Press Space to toggle between horror and back.

A number of changes occur when horror mode is turned on:

• The background translates faster and the opposite way. The image also changes to something else. I did this by including both as textures in the shader and picking between them based on the material parameter input.
• Similarly, the turntable camera rotates faster and the opposite way.
• The vignette gets replaced. Instead, I use the scribble texture from above as an interpolation value between a pure red color and the scene color. This gives it the "veiny" look. I also randomly offset the texture UV with time.
• I change the door's material to a modified version of the selected surface shader from earlier. In particular, shadows are removed and colors are adjusted to red and black. The phasing speed is also sped up.
• Laptop screen is replaced with another image. Same method as the background: simple logic switch in the laptop screen shader.