> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/SnowyMouse/chimera/llms.txt
> Use this file to discover all available pages before exploring further.

# Visual Enhancements

> Shader fixes, rendering improvements, and visual quality enhancements

Chimera provides extensive visual enhancements to restore Xbox-accurate rendering and improve visual quality beyond what Gearbox shipped.

## Shader Restoration

Gearbox introduced numerous shader regressions when porting Halo to PC. Chimera restores Xbox-accurate rendering.

### Shader Transparent Generic

One of the most significant improvements - restoring a **completely missing shader type**.

<Warning>
  **Gearbox removed** the `shader_transparent_generic` shader type from Halo PC entirely, breaking many visual effects.
</Warning>

**What Chimera Does**:

```cpp theme={null}
// Chimera re-implements shader_transparent_generic using Direct3D 9
// Supports all original Xbox shader features:
// - Multi-stage blending
// - Complex texture operations  
// - Fog integration
// - Proper alpha blending
```

**Location**: `src/chimera/rasterizer/shader_transparent_generic.cpp`

**Impact**:

* Transparent surfaces render correctly
* Glass effects work properly
* Environmental effects display as intended

### Environmental Bump Mapping

Fixes bump mapping on environmental surfaces.

**Command**: `chimera_force_alternate_bump_attenuation`

```bash theme={null}
chimera_force_alternate_bump_attenuation true
```

<Tabs>
  <Tab title="Default Behavior">
    Only applies alternate bump attenuation to shader\_environment tags with the appropriate flag set.
  </Tab>

  <Tab title="Forced (Command)">
    Forces alternate bump attenuation method for all environmental bump mapping.
  </Tab>
</Tabs>

### Specular Lighting

Restores proper specular highlights on surfaces.

**Location**: `src/chimera/fix/specular_memes.cpp`

### Fog Rendering

Fixes fog not rendering correctly in campaign levels.

<Info>
  **Example**: Assault on the Control Room's atmospheric sky fog now works as intended.
</Info>

**Impact**:

* Proper atmospheric effects
* Distance fog works correctly
* Environmental ambiance restored

### Water and Weather

Fixes for water and weather effects.

**Improvements**:

* Water shader rendering
* Weather particle effects
* Rain and snow properly rendered

**Locations**:

* `src/chimera/fix/water_fix.cpp`
* `src/chimera/fix/weather_fix.cpp`

## Resolution-Independent Rendering

Many visual elements in Halo PC were hardcoded to specific resolutions. Chimera makes them scale properly.

### Sun and Lens Flares

**Problem**: Lens flares drawn at set pixel count regardless of resolution.

**Solution**: Scale by 768p for consistency across resolutions.

```cpp theme={null}
// Before: 100 pixels (tiny at 4K)
// After: Scales proportionally to 768p baseline
```

### Zoom Blur

Improved zoom blur quality and scaling.

**Enhancements**:

* Blur radius scales by 480p (not hardcoded)
* Increased effect resolution
* Better quality at high resolutions
* Fixes blur looking "bad" at high res

**Disable it**:

```bash theme={null}
chimera_block_zoom_blur true
```

### HUD Elements

HUD numbers and elements now scale correctly.

**Fixed**:

* HUD numbers no longer oversized at high resolution
* Proper scaling for modified high-res HUD elements

## Limit Increases

Chimera increases rendering and game limits for modern content.

<AccordionGroup>
  <Accordion title="BSP Polygon Limit">
    **Original**: \~6,000-10,000 polygons

    **Chimera**: **32,767 polygons**

    ```cpp theme={null}
    #define BSP_POLY_LIMIT 0x7FFE  // 32,766
    ```

    Allows complex maps without polygon limit issues.
  </Accordion>

  <Accordion title="Visible Object Limit">
    **Original**: 256 objects

    **Chimera**: **1,024 objects**

    Maps with many objects no longer break rendering.
  </Accordion>

  <Accordion title="Draw Distance">
    **Original**: \~1,500 world units

    **Chimera**: **2,250 world units (\~6.86 km)**

    See further across large maps.
  </Accordion>
</AccordionGroup>

<Note>
  **Performance Impact**: None unless you play maps that exceed the original limits. The increases are capacity, not forced usage.
</Note>

**Location**: `src/chimera/fix/extend_limits.hpp`

## Anisotropic Filtering

Enhanced anisotropic filtering beyond base game capabilities.

**Features**:

* Applies to **individual objects**, not just level geometry
* Configurable filtering level
* Higher quality than Halo's built-in filtering

**Configuration**:

<CodeGroup>
  ```ini chimera.ini theme={null}
  [video_mode]
  af_level=16  ; Chimera default (base game: 8)
  ```

  ```bash Console Command theme={null}
  chimera_af true   ; Enable enhanced AF
  chimera_af false  ; Disable
  ```
</CodeGroup>

**Location**: `src/chimera/fix/af.cpp`

## Model Detail

Force highest LOD (Level of Detail) for all models.

**Command**: `chimera_model_detail`

```bash theme={null}
chimera_model_detail true  ; Always use highest quality models
```

<Info>
  **Exception**: Cryo tube model always scales by 480p to prevent the "4K headless chief" glitch.
</Info>

**Benefits**:

* Highest quality models at all distances
* Consistent visual quality
* Better for screenshots/videos

**Trade-off**: Slightly higher GPU usage on very old hardware.

## Decal Improvements

### Z-fighting Reduction

Reduces flickering between decals and level geometry.

**The Problem**:

```cpp theme={null}
// Floating point precision loss at distance from map center
// Causes Z-fighting (flickering surfaces)
```

**The Solution**: Chimera adjusts depth bias for decals to minimize fighting.

### Floor Decal Fix

Fixes floor decals rendering incorrectly.

**Location**: `src/chimera/fix/floor_decal_memery.cpp`

## Screen Effects

### Camera Shake

Frame-rate independent camera shake effects.

**Fixed**: Explosions and impacts now shake camera correctly at any FPS.

### Screen Effects

Various screen effect fixes.

**Location**: `src/chimera/fix/screen_effect_fix.cpp`

## Color and Rendering

### Blue 32-bit Color Fix

Fixes 32-bit color rendering issues.

**Location**: `src/chimera/fix/blue_32bit_color_fix.cpp`

### Bitmap Format Support

Expanded support for various bitmap formats.

**Location**: `src/chimera/fix/bitmap_formats.cpp`

**Improvements**:

* Additional texture formats
* Better compression support
* Higher quality texture loading

### Glass Rendering

Improved glass shader rendering.

**Location**: `src/chimera/fix/glass_fix.hpp`

## Particle and Effect Improvements

### Particle Interpolation

Smooth particle movement at high frame rates.

**Interpolated**:

* Explosions
* Smoke effects
* Bullet tracers
* Environmental particles

### Contrails

Fixed contrail rendering at high FPS.

**Examples**:

* Rocket trails
* Vehicle exhaust
* Grenade trails

### Effect Shaders

Various effect shader fixes.

**Location**: `src/chimera/fix/effect_shader_fix.hpp`

## Vertex and Geometry Rendering

### Vertex Shaders

Improved vertex shader handling.

**Location**: `src/chimera/rasterizer/rasterizer_vertex_shaders.cpp`

### Transparent Geometry

Enhanced transparent geometry rendering.

**Location**: `src/chimera/rasterizer/rasterizer_transparent_geometry.cpp`

**Improvements**:

* Better sorting
* Proper alpha blending
* Reduced artifacts

## Visual Quality Commands

Many visual enhancements can be toggled via console commands:

<CardGroup cols={2}>
  <Card title="FOV" icon="expand" href="/commands/fov">
    Adjust field of view
  </Card>

  <Card title="Anisotropic Filtering" icon="image" href="/commands/af">
    Enable enhanced AF
  </Card>

  <Card title="Model Detail" icon="cube" href="/commands/model-detail">
    Force highest LOD models
  </Card>

  <Card title="Widescreen Fix" icon="tv" href="/commands/widescreen-fix">
    Fix HUD for widescreen
  </Card>

  <Card title="Block Zoom Blur" icon="eye-slash" href="/commands/block-zoom-blur">
    Disable zoom blur effect
  </Card>

  <Card title="Safe Zones" icon="crop" href="/commands/safe-zones">
    Adjust HUD margins
  </Card>
</CardGroup>

## Configuration Options

### Video Mode Settings

Extensive video configuration in `chimera.ini`:

```ini theme={null}
[video_mode]
enabled=1
width=auto
height=auto
refresh_rate=0        ; Use system default
vsync=0               ; Double buffer vsync
windowed=0            ; Windowed mode
borderless=0          ; Borderless fullscreen
af_level=16           ; Anisotropic filtering level
```

### Optimal Defaults

Enable all recommended visual enhancements:

```ini theme={null}
[halo]
optimal_defaults=1
```

This automatically enables:

* `chimera_af true`
* `chimera_model_detail true`
* `chimera_fov auto`
* `chimera_uncap_cinematic true`
* And more!

## Performance Considerations

<Tabs>
  <Tab title="Modern Hardware">
    **Negligible impact** - All enhancements run smoothly on hardware from the last 10+ years.
  </Tab>

  <Tab title="Older Hardware">
    Consider disabling:

    * `chimera_model_detail` (LOD forcing)
    * High AF levels (reduce `af_level`)
    * Font overrides (slight overhead)
  </Tab>

  <Tab title="Benchmarking">
    Use `chimera_show_fps` to monitor performance:

    ```bash theme={null}
    chimera_show_fps true
    ```
  </Tab>
</Tabs>

## Technical Implementation

Key rendering code locations:

```
src/chimera/rasterizer/
├── rasterizer.cpp                      # Core rasterizer
├── rasterizer_vertex_shaders.cpp       # Vertex shaders
├── rasterizer_transparent_geometry.cpp # Transparency
└── shader_transparent_generic.cpp      # Generic shaders

src/chimera/fix/
├── af.cpp                    # Anisotropic filtering
├── extend_limits.hpp         # Limit increases
├── fov_fix.cpp              # FOV calculations
├── model_detail.cpp         # LOD control
├── sun_fix.cpp              # Lens flare scaling
├── z_fighting.cpp           # Depth fighting
└── bitmap_formats.cpp       # Texture formats
```