camera-proxy

Direct3D9 proxy DLL for RTX Remix camera/transform reconstruction.

This project wraps IDirect3D9 and IDirect3DDevice9, inspects vertex shader constant uploads, reconstructs camera transforms, and forwards fixed-function WORLD / VIEW / PROJECTION state before draw calls so Remix can consume consistent matrices in programmable DX9 games.

What the current main branch does

• Caches matrix candidates from SetVertexShaderConstantF uploads.
• Classifies matrices deterministically (World/View/Projection) using structural checks.
• Supports register overrides (ViewMatrixRegister, ProjMatrixRegister, WorldMatrixRegister) when a game uses known fixed slots.
• Emits SetTransform(D3DTS_WORLD/VIEW/PROJECTION) at draw time (DrawPrimitive, DrawIndexedPrimitive, DrawPrimitiveUP, DrawIndexedPrimitiveUP).
• Falls back to identity for missing matrix slots to keep fixed-function state valid.

Detection and reconstruction paths

1) Deterministic structural detection

When AutoDetectMatrices=1, uploaded 4x4 / 4x3 ranges are analyzed and classified:

• Projection: perspective-style structure + FOV validation (MinFOV, MaxFOV).
• View: strict camera-style affine/orthonormal checks.
• World: affine matrix that is not classified as strict view.

Optional probes:

• ProbeTransposedLayouts=1 checks one transposed candidate pass.
• ProbeInverseView=1 allows inverse-view style view recovery checks.

2) Optional combined-MVP decomposition fallback

If full W/V/P is not resolved, combined MVP decomposition can be enabled:

• EnableCombinedMVP
• CombinedMVPRequireWorld
• CombinedMVPAssumeIdentityWorld
• CombinedMVPForceDecomposition
• CombinedMVPLogDecomposition

3) Optional experimental custom projection fallback

For difficult titles, an experimental projection fallback can be enabled:

• Manual 4x4 projection matrix mode.
• Auto-generated projection mode (FOV / near / far / aspect / handedness controls).
• Optional override flags for detected projection and combined-MVP projection.

Relevant keys are prefixed with ExperimentalCustomProjection* in camera_proxy.ini.

Game profiles

GameProfile can switch from general structural detection to game-aware register mapping:

• MetalGearRising
  • Projection c4-c7
  • ViewProjection c8-c11 (proxy derives View)
  • World c16-c19
  • Tracks optional WorldView c20-c23
• DevilMayCry4 (or DMC4)
  • Combined MVP c0-c3
  • World c0-c3
  • View c4-c7
  • Projection c8-c11

If no profile is set, the proxy uses structural detection + optional register overrides.

Overlay and runtime controls

Built-in ImGui overlay includes:

• Camera matrix display/state source info.
• Shader constant inspection and editing tools.
• Optional memory scanner panel.
• In-overlay logs.

Runtime controls:

• ImGuiScalePercent for global overlay scaling.
• Hotkeys (default):
  • F10 menu toggle (HotkeyToggleMenuVK)
  • F9 pause rendering (HotkeyTogglePauseVK)
  • F8 emit cached matrices (HotkeyEmitMatricesVK)
  • F7 reset matrix register overrides (HotkeyResetMatrixOverridesVK)

Setup

1. Install RTX Remix runtime files in your game directory.
2. Rename Remix runtime DLL to d3d9_remix.dll (or set RemixDllName).
3. Copy this project's built d3d9.dll into the game directory.
4. Copy camera_proxy.ini into the same directory.
5. Launch the game and toggle the overlay with F10 (default).

Build

Prerequisites

• Visual Studio 2019 or 2022 with C++ workload
• Windows SDK (included with Visual Studio)
• ImGui source files in imgui/ subdirectory

Option A (Visual Studio Developer Command Prompt - Recommended)

For X64 builds (default):

1. Open "x64 Native Tools Command Prompt for VS" from Start Menu
2. Navigate to the project directory
3. Run:

build.bat

or explicitly:

build.bat x64

For X86 builds (32-bit):

1. Open "x86 Native Tools Command Prompt for VS" from Start Menu
2. Run:

build.bat x86

Option B (generic shell script that locates VS toolchain)

do_build.bat

Build Output

• Default output: d3d9.dll (architecture matches the command prompt environment)
• The build script will warn if you're in the wrong architecture environment

Architecture Verification

The DLL logs its build architecture on startup. Check camera_proxy.log for:

Build architecture: x64 (64-bit)
Pointer size: 8 bytes
Size of uintptr_t: 8 bytes

If you see x86 (32-bit) and Pointer size: 4 bytes, you built for 32-bit.

Troubleshooting X64 Builds

1. "d3d9_remix.dll not found" error

   • Ensure RTX Remix's d3d9.dll is renamed to d3d9_remix.dll in the game directory
   • Check camera_proxy.log for the exact paths being searched
   • Verify the Remix DLL matches your game's architecture (X64 game needs X64 Remix)

2. Menu not appearing (F10)

   • Check camera_proxy.log for ImGui initialization errors
   • Ensure the game has focus when pressing F10
   • Try disabling fullscreen and using windowed mode

3. Game crashes on startup

   • Verify architecture mismatch: X64 proxy with X86 game or vice versa
   • Check that d3d9_remix.dll exists and is valid
   • Review camera_proxy.log for loading errors

4. Matrices not detected

   • Enable LogAllConstants=1 in camera_proxy.ini
   • Use the Constants tab in the overlay to inspect shader uploads
   • Try different game profiles or manual register overrides

Key config options

See camera_proxy.ini for complete comments and defaults. Commonly used keys:

• Runtime/output: UseRemixRuntime, RemixDllName, EmitFixedFunctionTransforms
• Detection: AutoDetectMatrices, ProbeTransposedLayouts, ProbeInverseView
• Register control: ViewMatrixRegister, ProjMatrixRegister, WorldMatrixRegister
• Profiles: GameProfile
• Fallbacks: EnableCombinedMVP, ExperimentalCustomProjection*
• UI/input: ImGuiScalePercent, Hotkey*
• Diagnostics: EnableLogging, LogAllConstants

Credits

• mencelot (original DMC4 camera proxy basis)
• cobalticarus92 (camera-proxy project)