skate-3-rust-engine/docs/retail-renderer.md

Retail renderer

The world material adapter follows Alex's native renderer at f6e0ae8. The reference files are scene.hlsl, scene_common.hlsli, scene_frame_cb.hlsli, and hdr.hlsl. This is a Bevy implementation of those shading equations, not a port of the game hooks or the whole renderer.

Implemented:

• World families 1–13: diffuse/lightmap squaring, the family lighting terms, decal art, macro overlay, normal/detail lighting and specular masks.
• Reflective-family cube sampling with all six faces and a complete mip chain.
• The shared HDR tone curve, including environmentdiffuse's reduced curve. The final output accounts for Bevy's sRGB conversion instead of applying gamma twice. The HUD is drawn after this pass.
• Alpha-tested world materials use the reference's 30/255 threshold in both colour and depth passes. Foliage is two-sided.
• Lightmaps remain bilinear, clamped and fixed at mip zero. Repeating world textures have mipmaps.
• All ten installed worlds resolve sky geometry/texture paths through their authored world collection inheritance. The parks inherit the default panorama; Downtown and Industrial override it. Sky X/Z follow the camera; Y comes from the selected render_locations chain, not camera height.
• The sky uses its material's diffuse and specular GUID bindings. The latter is the 512x16 radial sun gradient: sine-angle lookup, squared RGB divided by saturated alpha + 0.01, then the material multiplier and scene exposure. material_sky/default.m_params[0] supplies scale 0.75 and multiplier 0.35; these are decoded inputs, not constants copied from one frame. This follows scene.hlsl's sky branch and skate3_native_scene.cpp's sky-bank layout.
• The selected render location supplies the normalized sun vector used by the sky and existing world tangent-sign terms. This adds no directional light energy or shadow map to imported worlds.

The converter reads scalar material channels at record offset 0x10. Earlier exports incorrectly read their string pointer and saved empty strings. Reconvert maps to obtain those constants and complete reflection cubes. Old packages still load; missing constants disable the relevant layer and single-face environment textures are not treated as cubes.

The VLT converter now adds array to array fields, retaining the existing type and data unchanged. array.items contains complete big-endian element hex strings without padding; capacity, element_size and alignment describe the source layout. Text arrays additionally retain decoded text_items before the binary bank is discarded. The layout follows VaultLib's VLTArrayType: four big-endian u16 header lanes followed by individually aligned elements. Alignment in the schema is a base-two exponent.

Skies can be refreshed independently of map/character conversion:

python -m tools.asset_pipeline.sky --game-root OWNED_EXTRACTED_GAME --assets PRIVATE_ASSET_ROOT

Use a private staging asset directory for experiments. This reads only the database pair and sky resources; it does not require an ISO or Blender. Legacy sky metadata retains its previous multiplier and has no sun gradient.

Treeline investigation

The missing forest in the supplied University / Super Ultra Mega Park comparison is not resolved by this change. The camera-relative WorldPresEntityOptimesh anchor from sub_82792900 is consistent with the sky placement above, but the decoded University panorama has mountains and city scenery, not a dense forest layer. Its RX2 contains one 380-triangle dome. The separate DIST_MegaPark archive contains 102 mesh parts and no tree mesh; it is not a source for additional trees at University's park.

The main University export retains 479 model assets, 8,546 mesh parts and 86 named TreeWall parts. Those named walls are outside the immediate park area; their absence at that location does not prove geometry is missing. Nearby proxy geometry demonstrably overlaps the main trees: in cell 350/-750, 451 of 456 proxy long-tree triangles match triangles in the 912-triangle main tree after quantization to one millimetre, independent of winding. The five nonmatching triangles are not evidence for an extra forest. The main tree's diffuse and transparent channels resolve the same DXT5 texture, with nonconstant alpha, and its baked lightmap is retained. The renderer already uses the retail cutoff in colour/depth and two-sided foliage.

No proxy geometry has been added. skate3_draw_distance.cpp documents the ProxyWorld/full-detail exchange; rendering both whole sets is not a valid fix. Identifying the specific missing silhouette now requires matched-camera reference evidence connecting it to a submitted mesh/material or a streaming collection. The two supplied images have different viewpoints. Native mip selection and regional/streaming state also remain unverified.

Remaining differences

This is not a claim of pixel parity. Native frame constants are supplied by game hooks in the reference; this engine does not yet recover that controller. Scene exposure 2.5, world material multiplier 1, and tree/proxy values still use documented day-capture defaults. Imported maps have no dynamic directional sun or realtime sun shadows: their world lighting comes from the baked lightmaps. Normal-map sign terms use the initial world's authored direction when new sky metadata is available; old packages retain the previous direction. Regional changes and the runtime environment controller are not implemented. Fog selection and its authored near/far/colour/power/max are retained in sky metadata, but the CPU transformation to native frame rows is not yet proven, so shader fog remains disabled. The selected material_fog/default must not be confused with the different fog_default collection.

Native water, character shaders, SSAO, SSR, bloom and volumetric lighting are not yet ported. The water arrays are recoverable now, but flowing-water normal/tangent unpacking, ocean PCA input bindings and the separate horizon water resource still need their own adapters. Character parity needs the native CAC-composed texture/mask inputs plus verified key/rim/specular and nine SH rows; portable GLB materials do not retain that contract. Reference post effects need their depth/normal/reflection inputs and native pass ordering; volumetric sun visibility also conflicts with the currently disabled world sun-shadow source. These gaps are not enabled using guessed settings. The character and unsupported world families still use Bevy materials beneath the shared tone curve. Reflection normals use the reference's analytic world-up construction; there has been no matched-camera pixel comparison against the recomp.

The shaders are embedded in the executable. Sky and map payloads are extracted from the user's game and must never be committed or bundled with releases.

Treeline investigation and diagnostic (2026-09-08)

The user's mega-park screenshots refer to the bowl/cliffs in University, not DIST_MegaPark (the separate create-a-park venue). A read-only decode of the installed University SKATE14 package found 8,546 materials, 1,645,617 render triangles, 1,180 tree-family mesh materials and all 86 TreeWall meshes from the source cache. TreeWall diffuse texture 0x2c70170a00053a88 retains its RGBA cutout, and the tree materials retain masked alpha and two-sided flags. A TOC audit of all 479 full models found no extra vertex or face buffers omitted by the parser.

Proxy comparisons must resolve mesh material GUIDs with _bind_material_groups_by_guid; mdl_parser.Mesh.name is in material-table order and can label proxy terrain as trees. With GUID bindings, the 14 proxy foliage meshes intersecting x=200..550, z=-850..-600 contain 3,878 distinct triangles; 3,813 match full geometry after unordered-vertex quantization to 1 mm. The small remainder does not establish absent trees (different triangulation/rounding also changes these keys). DMO_University and DMO_Global contain movable props, not a second background forest. These checks do not prove visual parity or a fix.

For a user-run discriminating capture, SKATE_DEBUG_FOLIAGE=1 renders tree-wall cards cyan and other tree-family surfaces magenta, opaque and unlit. Geometry, camera, depth testing and occlusion remain authored. This bypasses texture alpha in both colour and depth passes without adding proxy geometry. Return to the reported viewpoint: solid foliage appearing in the missing area implicates the normal shading/alpha path; an empty area requires checking placement, camera or source selection. Unset the variable to restore normal rendering. This diagnostic has been prepared without launching the game.