Investigate: built-in ReShade-style user shader effects (load .fx effects in our post chain)

sky_line commented

2026-09-29 22:17:53 +00:00

Owner

Investigate a built-in, ReShade-style user shader post-processing stack: load community effect files and run them inside our own frame, instead of people injecting ReShade on top of the viewer.

Why built in beats injected ReShade

Correct inputs. Injected ReShade has to guess which depth buffer is the scene (often wrong on Vulkan, flips/jitters with TAA, breaks with render scale #181). We can hand effects the real linear scene, unjittered display depth, normals (thin G-buffer), motion vectors -- data ReShade rarely gets reliably.
Right place in the frame. Effects run on the world only: before the UI, HUDs, name tags and chat (injected ReShade blurs/colours the UI too). Choice of injection point: linear HDR (pre-tonemap), after tonemap, or after Lightbox grading.
Snapshots. Effects apply to Snapshot / 360 / high-res captures, which injected ReShade can't do at custom sizes.
No external install, no anti-cheat-style DLL injection questions, works the same on Linux and Windows.

What to investigate

Effect language. Can we compile ReShade FX (.fx) directly? ReShade's effect compiler (reshadefx, BSD-3) emits SPIR-V. Check: license compatibility (LGPL viewer), build it as a 3p lib or vendor it, how much of the FX runtime semantics (techniques, passes, render targets, uniform annotations, source = special values like timer / frame count / mouse) we need to host. Alternative: our own simpler GLSL effect format (less compatible, less work).
Runtime. Per-effect render targets and passes on the VK post chain (dynamic rendering, one pipeline per pass), texture resources from the effect package, hot reload, GPU timer per effect.
Inputs mapping. ReShade's ReShade::BackBuffer / DepthBuffer conventions -> our HDR scene / tonemapped image / display depth (#181 recordDepthUpscale) / normals / motion. HDR vs LDR expectations of existing effects.
UI. Effect list with enable/order, per-uniform controls generated from annotations, presets (save/load, share), probably inside Lightbox.
Safety. User shaders run on the GPU only; guard against effects that hang the GPU (timeouts -> DEVICE_LOST, #135): per-effect disable on crash, safe-mode start.
Compatibility sample. Try a handful of popular effect packs (e.g. qUINT, iMMERSE-free, SweetFX, prod80) and note what breaks.

Output

A short design note + a go/no-go and size estimate, then implementation tickets.

Related: Lightbox (#111, #112), render scale (#181), temporal pipeline (#84), photo later (#118), device-lost handling (#135).

Investigate a built-in, ReShade-style user shader post-processing stack: load community effect files and run them inside our own frame, instead of people injecting ReShade on top of the viewer. ### Why built in beats injected ReShade - **Correct inputs.** Injected ReShade has to guess which depth buffer is the scene (often wrong on Vulkan, flips/jitters with TAA, breaks with render scale #181). We can hand effects the real linear scene, **unjittered display depth, normals (thin G-buffer), motion vectors** -- data ReShade rarely gets reliably. - **Right place in the frame.** Effects run on the world only: before the UI, HUDs, name tags and chat (injected ReShade blurs/colours the UI too). Choice of injection point: linear HDR (pre-tonemap), after tonemap, or after Lightbox grading. - **Snapshots.** Effects apply to Snapshot / 360 / high-res captures, which injected ReShade can't do at custom sizes. - **No external install**, no anti-cheat-style DLL injection questions, works the same on Linux and Windows. ### What to investigate 1. **Effect language.** Can we compile ReShade FX (`.fx`) directly? ReShade's effect compiler (`reshadefx`, BSD-3) emits SPIR-V. Check: license compatibility (LGPL viewer), build it as a 3p lib or vendor it, how much of the FX runtime semantics (techniques, passes, render targets, `uniform` annotations, `source =` special values like timer / frame count / mouse) we need to host. Alternative: our own simpler GLSL effect format (less compatible, less work). 2. **Runtime.** Per-effect render targets and passes on the VK post chain (dynamic rendering, one pipeline per pass), texture resources from the effect package, hot reload, GPU timer per effect. 3. **Inputs mapping.** ReShade's `ReShade::BackBuffer` / `DepthBuffer` conventions -> our HDR scene / tonemapped image / display depth (#181 `recordDepthUpscale`) / normals / motion. HDR vs LDR expectations of existing effects. 4. **UI.** Effect list with enable/order, per-uniform controls generated from annotations, presets (save/load, share), probably inside Lightbox. 5. **Safety.** User shaders run on the GPU only; guard against effects that hang the GPU (timeouts -> DEVICE_LOST, #135): per-effect disable on crash, safe-mode start. 6. **Compatibility sample.** Try a handful of popular effect packs (e.g. qUINT, iMMERSE-free, SweetFX, prod80) and note what breaks. ### Output A short design note + a go/no-go and size estimate, then implementation tickets. Related: Lightbox (#111, #112), render scale (#181), temporal pipeline (#84), photo later (#118), device-lost handling (#135).

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2026-09-29 22:17:53 +00:00

sky_line added this to the Slipstream project

2026-10-06 15:04:15 +00:00

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2026-10-08 06:28:03 +00:00

Epic: built-in effects stack (ReShade FX compatible) + cel-shading avatars #542

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2026-10-08 06:28:03 +00:00

FX P0: vendor reshadefx (BSD-3) + SPIR-V smoke test — go/no-go gate #543

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2026-10-08 06:28:03 +00:00

FX P1: effects runtime on the VK post chain (display injection point, BackBuffer/DepthBuffer) #544

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2026-10-08 06:28:03 +00:00

FX P2: Effects page in Photo Studio + ReShade .ini presets #545

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2026-10-08 06:28:03 +00:00

FX P3: safety — non-fatal user content, device-lost quarantine, safe start, VRAM cap #546

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2026-10-08 06:28:03 +00:00

FX P4: effects in snapshots (custom size, supersampled, 360 policy) #547

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2026-10-08 06:28:04 +00:00

FX P5: Slipstream extensions — HDR point, normals/motion/avatar-mask semantics, per-effect scope #548

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2026-10-08 06:28:04 +00:00

Cel P6: avatar mask — per-pixel avatar id from the GPU-driven pre-pass #549

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2026-10-08 06:28:04 +00:00

Cel P7: built-in cel shading — toon lighting + outlines, whole scene or avatars only #550

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2026-10-08 06:28:04 +00:00

FX P8: compatibility sweep (SweetFX, prod80, qUINT, iMMERSE free, Lilium HDR) + gap fixes #551

sky_line commented

2026-10-08 06:28:04 +00:00

Author

Owner

Investigation done. Design note + plan: epic #542.

Go / no-go:

Cel shading (first built-in, optional avatars-only): GO now. It's native: toon ramp in the shared lightSurface(), an avatar-id mask from the GPU-driven pre-pass, and a pre-TAA outline compute. It doesn't depend on the ReShade runtime (#549, #550).
ReShade FX compatibility: GO, contingent on P0 (#543). Vendor reshadefx (BSD-3; it emits SPIR-V directly, so no glslang/shaderc) and prove ≥ 90% of SweetFX / prod80 / reshade-shaders compile and validate. If it fails, fall back to our own GLSL format for built-ins only.

Key findings:

Default injection point: after FXAA/SMAA, before RLVa sphere and Lightbox final (reusing prepareFinal(force)). That keeps it pre-snapshot-capture and pre-HUD/UI.
displayDepth() is jittered at render scale 1 under TAA, so FX depth needs the depth-upscale unjitter at 1:1 too.
Our depth has no stencil, so FX needs its own stencil attachment.
Deferred G-buffer isn't used offscreen, so the avatar mask must come from the pre-pass, not G2.
BUFFER_WIDTH/HEIGHT are compile-time, so custom-size snapshots need a recompile + targets.

Licensing:

reshadefx is BSD-3 and ReShade.fxh is CC0, so both can ship.
ReShadeUI.fxh has no licence, so we write a clean-room copy.
qUINT / iMMERSE (no redistribution) and Lilium HDR (GPL-3) are user-installed only.
SweetFX / prod80 are MIT, but we bundle nothing in v1.

Leaving this open for the owner's decision.

Investigation done. Design note + plan: **epic #542**. **Go / no-go:** - **Cel shading (first built-in, optional avatars-only): GO now.** It's native: toon ramp in the shared `lightSurface()`, an avatar-id mask from the GPU-driven pre-pass, and a pre-TAA outline compute. It doesn't depend on the ReShade runtime (#549, #550). - **ReShade FX compatibility: GO, contingent on P0** (#543). Vendor reshadefx (BSD-3; it emits SPIR-V directly, so no glslang/shaderc) and prove ≥ 90% of SweetFX / prod80 / reshade-shaders compile and validate. If it fails, fall back to our own GLSL format for built-ins only. **Key findings:** - Default injection point: after FXAA/SMAA, before RLVa sphere and Lightbox final (reusing `prepareFinal(force)`). That keeps it pre-snapshot-capture and pre-HUD/UI. - `displayDepth()` is jittered at render scale 1 under TAA, so FX depth needs the depth-upscale unjitter at 1:1 too. - Our depth has no stencil, so FX needs its own stencil attachment. - Deferred G-buffer isn't used offscreen, so the avatar mask must come from the pre-pass, not G2. - `BUFFER_WIDTH/HEIGHT` are compile-time, so custom-size snapshots need a recompile + targets. **Licensing:** - reshadefx is BSD-3 and `ReShade.fxh` is CC0, so both can ship. - `ReShadeUI.fxh` has no licence, so we write a clean-room copy. - qUINT / iMMERSE (no redistribution) and Lilium HDR (GPL-3) are user-installed only. - SweetFX / prod80 are MIT, but we bundle nothing in v1. Leaving this open for the owner's decision.

sky_line commented

2026-10-09 04:40:37 +00:00

Author

Owner

Investigation complete: go/no-go and design plan are written up in epic #542 (cel shading and ReShade FX phases are tracked as #543-#551).

sky_line closed this issue

2026-10-09 04:40:37 +00:00

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2026-10-23 03:06:10 +00:00

Effects: bundle a curated MIT starter pack (SweetFX + prod80) with shipped presets #957