adminandClaude Fable 5
bdce9ea0c8
HeroCutoutLit.shader and its HeroCutout.hlsl include are in active use (hero cutout occluder material); Assets/Shaders/ is the established home for shader code. GUIDs preserved via .meta move, relative include path unchanged - no references break. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
80 lines
4.2 KiB
HLSL
80 lines
4.2 KiB
HLSL
#ifndef HERO_CUTOUT_INCLUDED
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#define HERO_CUTOUT_INCLUDED
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// World-space "hero cutout": clips occluder fragments that lie inside a CONE running from the camera
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// (apex) to the player (target). Everything BETWEEN the camera and the target within the cone is
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// punched see-through; geometry well behind the target stays solid - so a wall the player stands in
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// front of still renders completely normally. The "between vs. behind" split is purely geometric
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// (position along the camera->target axis), not a depth-buffer bias.
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//
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// That far split is FEATHERED on BOTH sides, never a hard plane: the cut fades out smoothly across a
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// band of +/- 'depthFeather' metres AROUND the target. So an occluder that crosses the player's depth
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// (a shelf board or wall running away from the camera) keeps fading just behind the player instead of
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// snapping to solid - no hard straight cut line where a depth plane would slice the surface. Only
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// geometry beyond that band (more than depthFeather behind the target) stays fully solid.
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//
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// Why a cone and not a cylinder: the cone's radius grows linearly with distance from the camera
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// (radius = paramRadius * along/len), so its *screen-space* footprint is constant regardless of how
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// far the occluder sits from the camera. A constant-world-radius cylinder would project bigger near
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// the lens and smaller near the target - a distorted hole. paramRadius is therefore the radius at the
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// target plane (metres); the cone tapers to 0 at the camera apex.
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//
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// Driven every frame by HeroCutout.cs (Shader.SetGlobalVector). These globals live OUTSIDE
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// UnityPerMaterial, so the SRP Batcher is unaffected. When disabled (_HeroCutoutTarget.w < 0.5, also
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// the zero-initialised default) ApplyHeroCutout early-outs and the shader renders exactly like URP/Lit.
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// _HeroCutoutTarget : xyz = player/target world position, w = enabled (0/1)
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// _HeroCutoutParams : x = cone radius at the target plane (m), y = edge feather at the target plane (m),
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// z = depth feather: half-width (m) of the soft fade band straddling the target
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float4 _HeroCutoutTarget;
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float4 _HeroCutoutParams;
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// Interleaved-gradient noise -> screen-door dither, gives the cone wall a soft edge with no extra
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// textures or includes.
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float HeroCutoutDither(float2 positionSS)
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{
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return frac(52.9829189 * frac(dot(positionSS, float2(0.06711056, 0.00583715))));
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}
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void ApplyHeroCutout(float4 positionCS)
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{
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if (_HeroCutoutTarget.w < 0.5)
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return;
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// Reconstruct this fragment's world position from screen UV + device depth.
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float2 screenUV = GetNormalizedScreenSpaceUV(positionCS);
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float3 posWS = ComputeWorldSpacePosition(screenUV, positionCS.z, UNITY_MATRIX_I_VP);
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float3 camPos = _WorldSpaceCameraPos.xyz;
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float3 axis = _HeroCutoutTarget.xyz - camPos;
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float len = length(axis);
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if (len < 1e-4)
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return;
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float3 dir = axis / len;
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// Distance along the camera->target axis (metres from the camera).
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float along = dot(posWS - camPos, dir);
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float depthFeather = max(_HeroCutoutParams.z, 1e-4);
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if (along <= 0.0 || along >= len + depthFeather) // behind the camera, or well behind the target -> solid
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return;
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// Perpendicular distance to the axis -> the cone test.
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float3 closest = camPos + dir * along;
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float radial = length(posWS - closest);
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// Cone: radius scales with distance from the camera (apex), so the on-screen hole stays the same
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// size at every occluder depth. t in (0,1]: 0 at the camera, 1 at the target plane.
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float t = along / len;
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float radius = _HeroCutoutParams.x * t;
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float feather = max(_HeroCutoutParams.y * t, 1e-4);
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float radialCut = 1.0 - smoothstep(radius - feather, radius, radial); // 1 inside the cone, 0 outside
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// Soft depth cap instead of a hard plane at the target: the cut fades out across a band straddling
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// the target - full strength up to (len - depthFeather), gone by (len + depthFeather). So an occluder
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// crossing the player's depth keeps fading just behind them rather than showing a hard straight edge.
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float axialCut = 1.0 - smoothstep(len - depthFeather, len + depthFeather, along);
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float cut = radialCut * axialCut;
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clip(HeroCutoutDither(positionCS.xy) - cut);
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}
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#endif
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