chore(upscaling): reduce ghosting near camera

[doodlum]

Summary by CodeRabbit

• Bug Fixes
  • Improved DLSS motion vector handling to reduce near-camera artifacts, resulting in smoother motion and more stable upscaling quality.
• Chores
  • Updated Upscaling component version to 1.1.1.

[coderabbitai]

Walkthrough

Updates an INI version in Upscaling.ini and changes DLSS motion vector handling in EncodeTexturesCS.hlsl by introducing a depth-driven nearFactor and blending between longest and current motion vectors based on screen depth.

Changes

Cohort / File(s)	Summary
Config version bump features/Upscaling/Shaders/Features/Upscaling.ini	Incremented [Info] Version from 1-1-0 to 1-1-1.
DLSS motion vector blending features/Upscaling/Shaders/Upscaling/EncodeTexturesCS.hlsl	Added nearFactor = smoothstep(4096.0 * 2.5, 0.0, SharedData::GetScreenDepth(depth)); replaced MotionVectorOutput = longestMotionVector with lerp(longestMotionVector, motionVector, nearFactor) in DLSS path.

Sequence Diagram(s)

sequenceDiagram
  autonumber
  participant RP as Render Pass
  participant CS as EncodeTexturesCS.hlsl (DLSS)
  participant SD as SharedData

  RP->>CS: Invoke compute shader
  CS->>SD: GetScreenDepth(depth)
  SD-->>CS: screenDepth
  CS->>CS: nearFactor = smoothstep(10240.0, 0.0, screenDepth)
  CS->>CS: blendedMV = lerp(longestMV, currentMV, nearFactor)
  CS-->>RP: MotionVectorOutput = blendedMV
  note over CS: Replaces direct longestMV output with depth-driven blend

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Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• fix: misc fixes #1474 — Also changes EncodeTexturesCS.hlsl motion-vector handling with guard restructuring around computations.
• chore(upscaling): improve upscaling for xess and fsr #1466 — Revises DLSS motion-vector selection logic, overlapping with the depth/neighborhood logic area touched here.

Suggested reviewers

• jiayev

Poem

I twitch my ears at version’s chime,
A nibble of depth, a blend in time—
Near fades to far, vectors align,
Pixels dance in a silky line.
Hop-hop! The frames now softly flow,
Carrots of clarity, onward we go! 🥕✨

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title Check	✅ Passed	The title succinctly and accurately describes the effort to reduce ghosting near the camera in the upscaling shader by blending motion vectors based on depth without extraneous details or noise.
Docstring Coverage	✅ Passed	No functions found in the changes. Docstring coverage check skipped.

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch upscaling-reduce-ghosting

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[github-actions]

Using provided base ref: b14bac3
Using base ref: b14bac3
Base commit date: 2025-10-06T15:51:22+01:00 (Monday, October 06, 2025 03:51 PM)
No actionable suggestions for changed features.

[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (1)

features/Upscaling/Shaders/Upscaling/EncodeTexturesCS.hlsl (1)

28-28: Depth-based blending factor is correctly implemented.

The inverted smoothstep edges produce the desired behavior: nearFactor = 1 for objects close to the camera (reducing ghosting) and nearFactor = 0 for distant objects (preserving temporal stability).

Consider documenting the threshold value (10240.0) with a comment explaining why this specific depth range was chosen, as it appears to be empirically tuned.

📜 Review details

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📥 Commits

Reviewing files that changed from the base of the PR and between b14bac3 and 5b6d731.

📒 Files selected for processing (2)

• features/Upscaling/Shaders/Features/Upscaling.ini (1 hunks)
• features/Upscaling/Shaders/Upscaling/EncodeTexturesCS.hlsl (2 hunks)

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📓 Path-based instructions (2)

**/*.{cpp,cxx,cc,c,h,hpp,hxx,hlsl,hlsli,fx,fxh,py}

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• features/Upscaling/Shaders/Upscaling/EncodeTexturesCS.hlsl

features/*/Shaders/**/*.{hlsl,hlsli,fx,fxh}

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Files:

• features/Upscaling/Shaders/Upscaling/EncodeTexturesCS.hlsl

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🔇 Additional comments (2)

features/Upscaling/Shaders/Features/Upscaling.ini (1)

2-2: Version bump is appropriate.

The version increment correctly reflects the motion vector blending changes in the associated DLSS shader.

features/Upscaling/Shaders/Upscaling/EncodeTexturesCS.hlsl (1)

62-62: Motion vector blending correctly addresses near-camera ghosting.

The lerp interpolation appropriately prioritizes the current motion vector for nearby objects (reducing ghosting) while preserving the longest motion vector for distant objects (maintaining temporal stability). The implementation aligns well with the PR objective.

[github-actions]

✅ A pre-release build is available for this PR:
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