fix: improve block light calculation

prismarine-viewer/examples/playground.ts

@@ -138,6 +138,7 @@ async function main () {
   viewer.entities.onSkinUpdate = () => {
     viewer.render()
   }
+  viewer.world.mesherConfig.enableLighting = false
 
   viewer.listen(worldView)
   // Load chunks

prismarine-viewer/viewer/lib/mesher/models.ts

@@ -300,6 +300,15 @@ function renderElement (world: World, cursor: Vec3, element, doAO: boolean, attr
     const maxy = element.to[1]
     const maxz = element.to[2]
 
+    const isConnectedWithTheBlock = (
+      (face === 'up' && maxy === 16) ||
+      (face === 'down' && miny === 0) ||
+      (face === 'north' && minz === 0) ||
+      (face === 'south' && maxz === 16) ||
+      (face === 'west' && minx === 0) ||
+      (face === 'east' && maxx === 16)
+    )
+
     const u = eFace.texture.u
     const v = eFace.texture.v
     const su = eFace.texture.su
@@ -349,7 +358,7 @@ function renderElement (world: World, cursor: Vec3, element, doAO: boolean, attr
 
     const aos: number[] = []
     const neighborPos = position.plus(new Vec3(...dir))
-    const baseLight = world.getLight(neighborPos) / 15
+    const baseLight = world.getLight(isConnectedWithTheBlock ? neighborPos : position) / 15
     for (const pos of corners) {
       let vertex = [
         (pos[0] ? maxx : minx),

prismarine-viewer/viewer/lib/mesher/test/mesherTester.ts

@@ -38,8 +38,22 @@ export const setup = (version, initialBlocks: [number[], string][]) => {
     }
     reload()
 
+    const getLights = () => {
+        return Object.fromEntries(getGeometry().faces.map(({ face, light }) => ([face, light * 15 - 2])))
+    }
+
+    const setLight = (x: number, y: number, z: number, val = 0) => {
+        // create columns first
+        chunk1.setBlockLight(pos.offset(x, y, z), 15)
+        chunk1.setSkyLight(pos.offset(x, y, z), 15)
+        chunk1.setBlockLight(pos.offset(x, y, z), val)
+        chunk1.setSkyLight(pos.offset(x, y, z), 0)
+    }
+
     return {
         mesherWorld,
+        setLight,
+        getLights,
         getGeometry,
         pos,
         mcData,

prismarine-viewer/viewer/lib/mesher/test/tests.test.ts

@@ -1,43 +1,44 @@
 import { test, expect } from 'vitest'
 import { setup } from './mesherTester'
+import { BlockNames } from '../../../../../src/mcDataTypes'
 
 const version = '1.18.1'
 
 const addPositions = [
-    // [[0, 0, 0], 'diamond_block'],
-    [[1, 0, 0], 'stone'],
-    [[-1, 0, 0], 'stone'],
-    [[0, 1, 0], 'stone'],
-    [[0, -1, 0], 'stone'],
-    [[0, 0, 1], 'stone'],
-    [[0, 0, -1], 'stone'],
+  // [[0, 0, 0], 'diamond_block'],
+  [[1, 0, 0], 'stone'],
+  [[-1, 0, 0], 'stone'],
+  [[0, 1, 0], 'stone'],
+  [[0, -1, 0], 'stone'],
+  [[0, 0, 1], 'stone'],
+  [[0, 0, -1], 'stone'],
 ] as const
 
 test('Known blocks are not rendered', () => {
-    const { mesherWorld, getGeometry, pos, mcData } = setup(version, addPositions as any)
+  const { mesherWorld, getGeometry, pos, mcData } = setup(version, addPositions as any)
 
-    let time = 0
-    let times = 0
-    const invalidBlocks = {}/*  as {[number, number]} */
-    for (const block of mcData.blocksArray) {
-        if (block.maxStateId! - block.minStateId! > 100) continue
-        for (let i = block.minStateId!; i <= block.maxStateId!; i++) {
-            if (block.transparent) continue
-            mesherWorld.setBlockStateId(pos, i)
-            const start = performance.now()
-            const { centerFaces, totalTiles, centerTileNeighbors } = getGeometry()
-            time += performance.now() - start
-            times++
-            if (centerFaces === 0 && centerTileNeighbors !== 0) {
-                if (invalidBlocks[block.name]) continue
-                invalidBlocks[block.name] = [i - block.minStateId!, centerTileNeighbors]
-                // console.log('INVALID', block.name, centerTileNeighbors, i - block.minStateId)
-            }
-        }
+  let time = 0
+  let times = 0
+  const invalidBlocks = {}/*  as {[number, number]} */
+  for (const block of mcData.blocksArray) {
+    if (block.maxStateId! - block.minStateId! > 100) continue
+    for (let i = block.minStateId!; i <= block.maxStateId!; i++) {
+      if (block.transparent) continue
+      mesherWorld.setBlockStateId(pos, i)
+      const start = performance.now()
+      const { centerFaces, totalTiles, centerTileNeighbors } = getGeometry()
+      time += performance.now() - start
+      times++
+      if (centerFaces === 0 && centerTileNeighbors !== 0) {
+        if (invalidBlocks[block.name]) continue
+        invalidBlocks[block.name] = [i - block.minStateId!, centerTileNeighbors]
+        // console.log('INVALID', block.name, centerTileNeighbors, i - block.minStateId)
+      }
     }
-    console.log('Average time', time / times)
-    // Fully expected
-    expect(invalidBlocks).toMatchInlineSnapshot(`
+  }
+  console.log('Average time', time / times)
+  // Fully expected
+  expect(invalidBlocks).toMatchInlineSnapshot(`
       {
         "creeper_head": [
           0,
@@ -94,3 +95,51 @@ test('Known blocks are not rendered', () => {
       }
     `)
 })
+
+
+test('Light calculated correctly', () => {
+  const result = {} as Record<string, any>
+  for (const block of ['oak_fence', 'oak_slab', 'soul_sand'] as BlockNames[]) {
+    const positions = [
+      [[0, 0, 0], block]
+    ]
+    const { getLights, setLight, reload } = setup('1.20.2', positions as any)
+    setLight(0, 0, 0, 5)
+    setLight(0, -1, 0, 10)
+    setLight(0, 1, 0, 10)
+    setLight(1, 0, 0, 10)
+    setLight(-1, 0, 0, 10)
+    setLight(0, 0, 1, 10)
+    setLight(0, 0, -1, 10)
+    reload()
+    result[block] = getLights()
+  }
+  expect(result).toMatchInlineSnapshot(`
+    {
+      "oak_fence": {
+        "down": 10,
+        "east": 5,
+        "north": 5,
+        "south": 5,
+        "up": 10,
+        "west": 5,
+      },
+      "oak_slab": {
+        "down": 10,
+        "east": 10,
+        "north": 10,
+        "south": 10,
+        "up": 5,
+        "west": 10,
+      },
+      "soul_sand": {
+        "down": 10,
+        "east": 10,
+        "north": 10,
+        "south": 10,
+        "up": 10,
+        "west": 10,
+      },
+    }
+  `)
+})

prismarine-viewer/viewer/lib/mesher/world.ts

@@ -44,17 +44,18 @@ export class World {
     // if (lightsCache.has(key)) return lightsCache.get(key)
     const column = this.getColumnByPos(pos)
     if (!column || !hasChunkSection(column, pos)) return 15
+    const posChunk = posInChunk(pos)
     let result = Math.min(
       15,
       Math.max(
-        column.getBlockLight(posInChunk(pos)),
-        Math.min(skyLight, column.getSkyLight(posInChunk(pos)))
+        column.getBlockLight(posChunk),
+        Math.min(skyLight, column.getSkyLight(posChunk))
       ) + 2
     )
     // lightsCache.set(key, result)
-    if (result === 2 && this.getBlock(pos)?.name.match(/_stairs|slab/)) { // todo this is obviously wrong
-      result = this.getLight(pos.offset(0, 1, 0))
-    }
+    // if (result === 2 && this.getBlock(pos)?.name.match(/_stairs|slab/)) { // todo this is obviously wrong
+    //   result = this.getLight(pos.offset(0, 1, 0))
+    // }
     if (isNeighbor && result === 2) result = 15 // TODO
     return result
   }
@@ -128,7 +129,8 @@ export class World {
 }
 
 // todo export in chunk instead
-const hasChunkSection = (column, pos) => {
+export const hasChunkSection = (column, pos) => {
+  pos = posInChunk(pos)
   if (column._getSection) return column._getSection(pos)
   if (column.skyLightSections) {
     return column.skyLightSections[getLightSectionIndex(pos, column.minY)] || column.blockLightSections[getLightSectionIndex(pos, column.minY)]