74 lines
4.0 KiB
Markdown
74 lines
4.0 KiB
Markdown
# BRIEF: NFS 2015-Style Wet Perma-Night Scene Setup (Raylib / C)
|
||
|
||
## 1. Goal
|
||
Transform an existing basic 3D scene (containing car model, road surfaces, and city building meshes with flat albedo textures) into a high-contrast, moody, wet perma-night aesthetic inspired by *Need for Speed (2015)*.
|
||
|
||
---
|
||
|
||
## 2. Technical Stack Context
|
||
- **Framework:** Raylib (C/C++)
|
||
- **Core APIs:** Custom GLSL Shaders (Shader / Fragment Shaders), `RenderTexture2D` (FBOs), `rlgl` for state/texture management.
|
||
- **Goal Output:** Modular shader code and pass-management architecture that runs efficiently on Raylib's forward renderer.
|
||
|
||
---
|
||
|
||
## 3. Implementation Roadmap & Execution Tasks
|
||
|
||
### Phase 1: Material & Wetness Shader (`wet_road.fs`)
|
||
Modify the primary object shader used for terrain/road surfaces to support a wetness model.
|
||
|
||
- [ ] **Inputs Needed:**
|
||
- `texture0` (Albedo / Diffuse)
|
||
- `texture1` (Normal Map)
|
||
- `texture2` (Roughness Map or Puddle Noise Mask)
|
||
- Uniform `float u_wetness` (Range: `0.0` to `1.0`)
|
||
- [ ] **Shader Logic Requirements:**
|
||
- **Albedo Darkening:** Darken base albedo by ~30–40% on wet areas (porous surfaces darken when saturated).
|
||
- **Roughness Modulation:** Force surface roughness down to near-mirror levels (`~0.02 - 0.1`) based on `u_wetness` and the puddle mask.
|
||
- **Normal Flattening for Puddles:** In high-puddle mask areas, lerp surface normals toward `vec3(0.0, 1.0, 0.0)` to simulate smooth standing water.
|
||
|
||
### Phase 2: Lighting & Emissive Setup
|
||
Configure scene lights and emissive materials for night contrast.
|
||
|
||
- [ ] **Global Ambient Light:** Lower global ambient color to a dark, cool navy (`RGB: 10, 15, 30`).
|
||
- [ ] **Emissive Material Handling:**
|
||
- Add support for an emissive map/uniform on neon signs, building windows, and car light meshes.
|
||
- Multiply emissive output by an intensity factor (`> 2.0`) to ensure they trigger the Bloom threshold in post-processing.
|
||
- [ ] **Point & Spot Lights:**
|
||
- Implement dynamic point lights for streetlights and headlights with quadratic distance attenuation (`1.0 / (att_const + att_linear * d + att_quad * d * d)`).
|
||
|
||
### Phase 3: Post-Processing Framebuffer Pipeline (`main.c`)
|
||
Set up offscreen rendering to enable screen-space passes.
|
||
|
||
- [ ] **Render Texture Setup:**
|
||
- Create a master `RenderTexture2D targetScene` FBO matching screen resolution.
|
||
- Create a secondary `RenderTexture2D pingPongBlur[2]` FBO pair for downscaled bloom processing.
|
||
- [ ] **Render Loop Flow:**
|
||
1. `BeginTextureMode(targetScene)` $\rightarrow$ Render all 3D geometry using object shaders.
|
||
2. `EndTextureMode()`
|
||
3. Extract bright pixels from `targetScene` to bloom FBO via threshold shader (`luminance > 0.7`).
|
||
4. Perform horizontal and vertical blur passes on the bright map.
|
||
5. Composite original scene + blurred bloom + final color grading onto the screen.
|
||
|
||
### Phase 4: Color Grading & Anamorphic Bloom Shader (`post_process.fs`)
|
||
Apply the final cinematic "lens" pass over the scene texture.
|
||
|
||
- [ ] **Heavy / Anamorphic Bloom:**
|
||
- Scale horizontal blur kernel radius larger than vertical to simulate anamorphic lens flares from streetlights and wet ground reflections.
|
||
- [ ] **High-Contrast Night LUT / Grading:**
|
||
- Crushed deep blacks (`#050508`).
|
||
- Cool cyan/teal shadows and warm orange/amber highlights for light sources.
|
||
- [ ] **Vignette & Lens Effects:**
|
||
- Radial vignette intensity dropping at screen edges.
|
||
- Subtle chromatic aberration (offset Red/Blue channels slightly near screen borders).
|
||
|
||
### Phase 5: Simple Reflection Pass (Ground / Car)
|
||
- [ ] Implement a basic planar reflection pass or sample a low-resolution cubemap probe inside the `wet_road.fs` fragment shader to give wet surfaces mirror-like reflections of the ambient sky and light sources.
|
||
|
||
---
|
||
|
||
## 4. Deliverables Checklist
|
||
1. `wet_material.fs` / `wet_material.vs`: Shader handling albedo darkening, normal mapping, and specular puddle blending.
|
||
2. `post_process.fs`: Screen-space shader combining Bloom, Color Grading, Vignette, and Chromatic Aberration.
|
||
3. Updated Raylib C loop establishing the `RenderTexture2D` pipeline and uniform bindings.
|