probably fix issue with phosphor crashing contraptions

src/main/java/com/simibubi/create/content/contraptions/components/structureMovement/ContraptionHandler.java

@@ -7,6 +7,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
+import com.simibubi.create.content.contraptions.components.structureMovement.render.ContraptionRenderDispatcher;
 import com.simibubi.create.foundation.utility.VecHelper;
 import com.simibubi.create.foundation.utility.WorldAttached;
 
@@ -17,7 +18,9 @@ import net.minecraft.entity.LivingEntity;
 import net.minecraft.nbt.CompoundNBT;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.World;
+import net.minecraftforge.api.distmarker.Dist;
 import net.minecraftforge.common.util.Constants.NBT;
+import net.minecraftforge.fml.DistExecutor;
 
 public class ContraptionHandler {
 

src/main/java/com/simibubi/create/content/contraptions/components/structureMovement/render/ContraptionRenderDispatcher.java

@@ -10,6 +10,10 @@ import com.simibubi.create.foundation.render.TileEntityRenderHelper;
 import com.simibubi.create.foundation.render.backend.FastRenderDispatcher;
 import com.simibubi.create.foundation.render.backend.Backend;
 import com.simibubi.create.foundation.utility.AnimationTickHolder;
+import com.simibubi.create.foundation.utility.Pair;
+import com.simibubi.create.foundation.utility.worldWrappers.PlacementSimulationWorld;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.IRenderTypeBuffer;
 import net.minecraft.client.renderer.Matrix4f;
@@ -30,9 +34,12 @@ import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ForkJoinPool;
 
 public class ContraptionRenderDispatcher {
-    public static final HashMap<Integer, RenderedContraption> renderers = new HashMap<>();
+    public static final Int2ObjectMap<RenderedContraption> renderers = new Int2ObjectOpenHashMap<>();
 
     public static void notifyLightUpdate(ILightReader world, LightType type, SectionPos pos) {
         for (RenderedContraption renderer : renderers.values()) {
@@ -82,16 +89,15 @@ public class ContraptionRenderDispatcher {
     }
 
     private static RenderedContraption getRenderer(World world, Contraption c) {
-        RenderedContraption renderer;
         int entityId = c.entity.getEntityId();
-        if (renderers.containsKey(entityId)) {
+        RenderedContraption contraption = renderers.get(entityId);
-            renderer = renderers.get(entityId);
+
-        } else {
+        if (contraption == null) {
-            renderer = new RenderedContraption(world, c);
+            contraption = new RenderedContraption(world, c);
-            renderers.put(entityId, renderer);
+            renderers.put(entityId, contraption);
         }
 
-        return renderer;
+        return contraption;
     }
 
     public static void renderLayer(RenderType layer, Matrix4f viewProjection, float camX, float camY, float camZ) {

src/main/java/com/simibubi/create/content/contraptions/components/structureMovement/render/RenderedContraption.java

@@ -34,7 +34,7 @@ import java.util.List;
 import java.util.Random;
 
 public class RenderedContraption {
-    private HashMap<RenderType, ContraptionModel> renderLayers = new HashMap<>();
+    private final HashMap<RenderType, ContraptionModel> renderLayers = new HashMap<>();
 
     public final PlacementSimulationWorld renderWorld;
 

src/main/java/com/simibubi/create/foundation/utility/worldWrappers/PlacementSimulationWorld.java

@@ -89,6 +89,10 @@ public class PlacementSimulationWorld extends WrappedWorld {
 		return true;
 	}
 
+	public BlockState getBlockState(int x, int y, int z) {
+		return getBlockState(scratch.setPos(x, y, z));
+	}
+
 	@Override
 	public BlockState getBlockState(BlockPos pos) {
 		BlockState state = blocksAdded.get(pos);

src/main/java/com/simibubi/create/foundation/utility/worldWrappers/chunk/WrappedChunk.java

@@ -30,11 +30,13 @@ import java.util.stream.Stream;
 
 public class WrappedChunk implements IChunk {
 
-    private final PlacementSimulationWorld world;
+    final PlacementSimulationWorld world;
-    private boolean needsLight;
+    boolean needsLight;
-    private final int x;
+    final int x;
-    private final int z;
+    final int z;
-    private final ChunkPos pos;
+    final ChunkPos pos;
+
+    private final ChunkSection[] sections;
 
     public WrappedChunk(PlacementSimulationWorld world, int x, int z) {
         this.world = world;
@@ -42,6 +44,12 @@ public class WrappedChunk implements IChunk {
         this.x = x;
         this.z = z;
         this.pos = new ChunkPos(x, z);
+
+        this.sections = new ChunkSection[16];
+
+        for (int i = 0; i < 16; i++) {
+            sections[i] = new WrappedChunkSection(this, i << 4);
+        }
     }
 
     @Override
@@ -57,6 +65,11 @@ public class WrappedChunk implements IChunk {
                 .map(Map.Entry::getKey);
     }
 
+    @Override
+    public ChunkSection[] getSections() {
+        return sections;
+    }
+
     @Nullable
     @Override
     public BlockState setBlockState(BlockPos p_177436_1_, BlockState p_177436_2_, boolean p_177436_3_) {
@@ -78,11 +91,6 @@ public class WrappedChunk implements IChunk {
         return null;
     }
 
-    @Override
-    public ChunkSection[] getSections() {
-        return new ChunkSection[0];
-    }
-
     @Override
     public Collection<Map.Entry<Heightmap.Type, Heightmap>> func_217311_f() {
         return null;

src/main/java/com/simibubi/create/foundation/utility/worldWrappers/chunk/WrappedChunkSection.java

@@ -0,0 +1,32 @@
+package com.simibubi.create.foundation.utility.worldWrappers.chunk;
+
+import net.minecraft.block.BlockState;
+import net.minecraft.world.chunk.ChunkSection;
+
+public class WrappedChunkSection extends ChunkSection {
+
+    public WrappedChunk owner;
+
+    public final int xStart;
+    public final int yStart;
+    public final int zStart;
+
+    public WrappedChunkSection(WrappedChunk owner, int yBase) {
+        super(yBase);
+        this.owner = owner;
+        this.xStart = owner.pos.getXStart();
+        this.yStart = yBase;
+        this.zStart = owner.pos.getZStart();
+    }
+
+    @Override
+    public BlockState getBlockState(int x, int y, int z) {
+        // ChunkSection#getBlockState expects local chunk coordinates, so we add to get back into world coords.
+        return owner.world.getBlockState(x + xStart, y + yStart, z + zStart);
+    }
+
+    @Override
+    public BlockState setBlockState(int p_177484_1_, int p_177484_2_, int p_177484_3_, BlockState p_177484_4_, boolean p_177484_5_) {
+        throw new IllegalStateException("Chunk sections should not be mutated in a fake world.");
+    }
+}