{
"schema_version": "engine_native_buffer_schema_v1",
"description": "Buffer schema for engine-native temporal buffer captures exported from real-time renderers (Unreal Engine, Unity, custom renderers).",
"required_buffers": [
{
"name": "current_color",
"semantic": "current_color",
"description": "Current frame pre-tonemapped linear RGB color. Captured after TAA input, before TAA resolve.",
"required": true,
"capture_point": "after_shading_before_taa",
"accepted_formats": ["exr_rgb32f", "png_rgb8", "json_rgb_f32", "raw_rgb32f"],
"preferred_format": "exr_rgb32f",
"recommended_bit_depth": "32-bit float per channel",
"channels": 3,
"channel_convention": "R, G, B in linear light (not gamma-corrected)",
"range": "[0, ∞) — HDR content may exceed 1.0",
"engine_specific": {
"unreal": "SceneColor after deferred shading, before r.TemporalAA",
"unity": "ColorTexture at BeforeTransparent injection point, before TemporalAA pass",
"custom": "Linear HDR color buffer at TAA input stage"
}
},
{
"name": "history_color",
"semantic": "history_color",
"description": "Previous resolved frame color, reprojected to current frame coordinates using motion vectors. This is the temporal history input to TAA.",
"required": true,
"capture_point": "taa_history_input",
"accepted_formats": ["exr_rgb32f", "png_rgb8", "json_rgb_f32", "raw_rgb32f"],
"preferred_format": "exr_rgb32f",
"recommended_bit_depth": "32-bit float per channel",
"channels": 3,
"channel_convention": "R, G, B reprojected to current frame coordinates",
"range": "[0, ∞)",
"engine_specific": {
"unreal": "HistoryColor buffer from TemporalAA pass inputs",
"unity": "TAA history buffer sampled at reprojected UV",
"custom": "Reprojected previous frame using supplied motion vectors"
}
},
{
"name": "motion_vectors",
"semantic": "motion_vectors",
"description": "Per-pixel motion vectors in screen-space pixel offset units. Each vector points from current pixel to corresponding pixel in the previous frame.",
"required": true,
"capture_point": "motion_vector_pass",
"accepted_formats": ["json_vec2_f32", "exr_rg32f", "raw_rg32f"],
"preferred_format": "exr_rg32f",
"recommended_bit_depth": "32-bit float per channel",
"channels": 2,
"channel_convention": "X = horizontal pixel offset (positive = samples from right in history), Y = vertical pixel offset (positive = samples from below in history)",
"coordinate_convention": "pixel_offset_to_prev",
"range": "unbounded; typical range ±resolution pixels for full-motion frames",
"note": "Some engines export motion vectors as normalized UV offsets — convert to pixel offsets by multiplying by resolution.",
"engine_specific": {
"unreal": "r.BasePassOutputsVelocity=1, VelocityBuffer pass — already in pixel offset space",
"unity": "MotionVectorTexture from MotionVectors render feature",
"custom": "Per-pixel (dx, dy) in pixel units pointing to previous frame position"
}
},
{
"name": "current_depth",
"semantic": "current_depth",
"description": "Per-pixel depth for the current frame. Must be monotonically increasing with distance from camera.",
"required": true,
"capture_point": "depth_prepass_or_gbuffer",
"accepted_formats": ["json_scalar_f32", "exr_r32f", "raw_r32f"],
"preferred_format": "exr_r32f",
"recommended_bit_depth": "32-bit float",
"channels": 1,
"depth_convention": "monotonic_larger_is_further",
"acceptable_conventions": ["linear_depth_z", "view_space_z", "ndc_depth_converted_to_linear"],
"not_acceptable": ["raw_NDC_reversed_Z_without_conversion"],
"note": "Reversed-Z NDC depth is NOT directly usable. Convert to linear depth before export.",
"engine_specific": {
"unreal": "SceneDepth (linear depth) from GBuffer — NOT HZB or reversed-Z NDC",
"unity": "CameraDepthTexture converted to linear depth via LinearEyeDepth()",
"custom": "Linear depth in world units or normalized linear depth"
}
},
{
"name": "current_normals",
"semantic": "current_normals",
"description": "Per-pixel view-space normals for the current frame. Used for disocclusion detection.",
"required": true,
"capture_point": "gbuffer",
"accepted_formats": ["json_vec3_f32", "exr_rgb32f", "raw_rgb32f"],
"preferred_format": "exr_rgb32f",
"recommended_bit_depth": "32-bit float per channel",
"channels": 3,
"normal_convention": "view_space_unit_vectors",
"channel_convention": "X, Y, Z unit vector; camera-facing surface has positive Z in view space",
"range": "Each component in [-1, 1]; magnitude = 1.0",
"engine_specific": {
"unreal": "GBufferB.xyz decoded from WorldNormal, transformed to view space",
"unity": "NormalTexture from G-buffer decoded, transformed to view space",
"custom": "View-space normal vectors, unit length"
}
}
],
"optional_buffers": [
{
"name": "history_depth",
"semantic": "history_depth",
"description": "Depth buffer from the previous frame, reprojected to current frame coordinates. If absent, a proxy is derived from the current depth using motion vector extrapolation. Labeled derived-low-confidence when absent.",
"required": false,
"absence_handling": "derive_from_current_depth_with_motion_extrapolation",
"absence_quality_label": "derived-low-confidence",
"accepted_formats": ["json_scalar_f32", "exr_r32f", "raw_r32f"]
},
{
"name": "history_normals",
"semantic": "history_normals",
"description": "Normal buffer from the previous frame, reprojected to current frame coordinates. If absent, history normals are approximated from the current normals. Labeled derived-low-confidence when absent.",
"required": false,
"absence_handling": "approximate_from_current_normals",
"absence_quality_label": "derived-low-confidence",
"accepted_formats": ["json_vec3_f32", "exr_rgb32f", "raw_rgb32f"]
},
{
"name": "roi_mask",
"semantic": "optional_mask",
"description": "Per-pixel ROI mask (1.0 = in ROI, 0.0 = not in ROI). If absent, a derived mask is computed from depth+normal discontinuities. Native mask is preferred for Demo A evaluation.",
"required": false,
"absence_handling": "derive_from_depth_normal_discontinuities",
"absence_quality_label": "derived-low-confidence",
"accepted_formats": ["json_scalar_f32", "exr_r32f", "raw_r32f", "png_rgb8_threshold"]
},
{
"name": "jitter",
"semantic": "optional_jitter",
"description": "Per-frame sub-pixel jitter offset used for TAA. Format: [jitter_x, jitter_y] in pixel units.",
"required": false,
"accepted_formats": ["json_metadata"]
},
{
"name": "camera_matrices",
"semantic": "optional_camera",
"description": "Camera view + projection matrices for the current and previous frames. Used for improved reprojection quality validation.",
"required": false,
"accepted_formats": ["json_metadata"]
},
{
"name": "history_validity_mask",
"semantic": "optional_variance",
"description": "Per-pixel mask indicating valid history pixels (1.0 = valid history, 0.0 = invalid/disocclusion). If absent, history validity is inferred from motion vector + depth consistency.",
"required": false,
"absence_handling": "infer_from_motion_depth_consistency",
"accepted_formats": ["json_scalar_f32", "exr_r32f"]
}
],
"metadata_schema": {
"format": "json_metadata",
"required_fields": [
{"name": "frame_index", "type": "integer", "description": "0-based index of current frame"},
{"name": "history_frame_index", "type": "integer", "description": "0-based index of previous frame"},
{"name": "width", "type": "integer", "description": "Frame width in pixels"},
{"name": "height", "type": "integer", "description": "Frame height in pixels"},
{"name": "source_kind", "type": "string", "description": "Always 'engine_native'"},
{"name": "real_external_data", "type": "boolean", "description": "true for real captures, false for placeholders"}
],
"optional_fields": [
{"name": "jitter_x", "type": "float", "description": "Sub-pixel jitter X in pixel units"},
{"name": "jitter_y", "type": "float", "description": "Sub-pixel jitter Y in pixel units"},
{"name": "exposure", "type": "float", "description": "Exposure value used for this frame"},
{"name": "scene_name", "type": "string", "description": "Human-readable scene identifier"}
]
},
"notes": [
"All required buffers must match in width and height. Shape mismatch is a hard rejection.",
"Color buffers must be in linear light. Gamma-encoded buffers will produce incorrect trust scores.",
"Motion vectors must be in pixel offset units. UV offset convention must be converted before import.",
"Depth must be monotonically increasing with distance. Reversed-Z NDC must be converted before export.",
"Normals must be view-space unit vectors. World-space normals must be transformed before export.",
"Optional buffers that are absent are labeled derived-low-confidence in all reports.",
"There is no acceptable substitute for real capture data. Do not use placeholder values for required buffers."
]
}