You spin me right round

- Seated Players now sync their camera rotation to the movement of the contraption (if possible)

src/main/java/com/simibubi/create/content/contraptions/AbstractContraptionEntity.java

@@ -870,10 +870,11 @@ public abstract class AbstractContraptionEntity extends Entity implements IEntit
 	public static class ContraptionRotationState {
 		public static final ContraptionRotationState NONE = new ContraptionRotationState();
 
-		float xRotation = 0;
+		public float xRotation = 0;
-		float yRotation = 0;
+		public float yRotation = 0;
-		float zRotation = 0;
+		public float zRotation = 0;
-		float secondYRotation = 0;
+		public float secondYRotation = 0;
+		
 		Matrix3d matrix;
 
 		public Matrix3d asMatrix() {

src/main/java/com/simibubi/create/content/contraptions/actors/seat/ContraptionPlayerPassengerRotation.java

@@ -0,0 +1,71 @@
+package com.simibubi.create.content.contraptions.actors.seat;
+
+import com.simibubi.create.content.contraptions.AbstractContraptionEntity;
+import com.simibubi.create.content.contraptions.AbstractContraptionEntity.ContraptionRotationState;
+import com.simibubi.create.content.trains.entity.CarriageContraptionEntity;
+import com.simibubi.create.foundation.utility.AngleHelper;
+import com.simibubi.create.foundation.utility.AnimationTickHolder;
+import com.simibubi.create.infrastructure.config.AllConfigs;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.util.Mth;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.entity.player.Player;
+
+public class ContraptionPlayerPassengerRotation {
+
+	static boolean active;
+	static int prevId;
+	static float prevYaw;
+	static float prevPitch;
+
+	public static void tick() {
+		active = AllConfigs.client().rotateWhenSeated.get();
+	}
+
+	public static void frame() {
+		Player player = Minecraft.getInstance().player;
+		if (!active)
+			return;
+		if (player == null || !player.isPassenger()) {
+			prevId = 0;
+			return;
+		}
+
+		Entity vehicle = player.getVehicle();
+		if (!(vehicle instanceof AbstractContraptionEntity contraptionEntity))
+			return;
+
+		ContraptionRotationState rotationState = contraptionEntity.getRotationState();
+
+		float yaw = AngleHelper.wrapAngle180((contraptionEntity instanceof CarriageContraptionEntity cce)
+			? cce.getViewYRot(AnimationTickHolder.getPartialTicks())
+			: rotationState.yRotation);
+
+		float pitch = (contraptionEntity instanceof CarriageContraptionEntity cce)
+			? cce.getViewXRot(AnimationTickHolder.getPartialTicks())
+			: 0;
+
+		if (prevId != contraptionEntity.getId()) {
+			prevId = contraptionEntity.getId();
+			prevYaw = yaw;
+			prevPitch = pitch;
+		}
+
+		float yawDiff = AngleHelper.getShortestAngleDiff(yaw, prevYaw);
+		float pitchDiff = AngleHelper.getShortestAngleDiff(pitch, prevPitch);
+
+		prevYaw = yaw;
+		prevPitch = pitch;
+
+		float yawRelativeToTrain = Mth.abs(AngleHelper.getShortestAngleDiff(player.getYRot(), -yaw - 90));
+		if (yawRelativeToTrain > 120)
+			pitchDiff *= -1;
+		else if (yawRelativeToTrain > 60)
+			pitchDiff *= 0;
+
+		player.setYRot((float) (player.getYRot() + yawDiff));
+		player.setXRot((float) (player.getXRot() + pitchDiff));
+	}
+
+}

src/main/java/com/simibubi/create/foundation/events/ClientEvents.java

@@ -7,6 +7,7 @@ import com.simibubi.create.AllPackets;
 import com.simibubi.create.Create;
 import com.simibubi.create.CreateClient;
 import com.simibubi.create.content.contraptions.ContraptionHandler;
+import com.simibubi.create.content.contraptions.actors.seat.ContraptionPlayerPassengerRotation;
 import com.simibubi.create.content.contraptions.actors.trainControls.ControlsHandler;
 import com.simibubi.create.content.contraptions.chassis.ChassisRangeDisplay;
 import com.simibubi.create.content.contraptions.minecart.CouplingHandlerClient;
@@ -166,6 +167,7 @@ public class ClientEvents {
 		CreateClient.VALUE_SETTINGS_HANDLER.tick();
 		ScrollValueHandler.tick();
 		NetheriteBacktankFirstPersonRenderer.clientTick();
+		ContraptionPlayerPassengerRotation.tick();
 	}
 
 	@SubscribeEvent
@@ -218,6 +220,8 @@ public class ClientEvents {
 		buffer.draw();
 		RenderSystem.enableCull();
 		ms.popPose();
+		
+		ContraptionPlayerPassengerRotation.frame();
 	}
 
 	@SubscribeEvent

src/main/java/com/simibubi/create/infrastructure/config/CClient.java

@@ -33,6 +33,8 @@ public class CClient extends ConfigBase {
 			Comments.ingameMenuConfigButtonOffsetX);
 	public final ConfigBool ignoreFabulousWarning = b(false, "ignoreFabulousWarning",
 		Comments.ignoreFabulousWarning);
+	public final ConfigBool rotateWhenSeated = b(true, "rotateWhenSeated",
+		Comments.rotatewhenSeated);
 
 	// custom fluid fog
 	public final ConfigGroup fluidFogSettings = group(1, "fluidFogSettings", Comments.fluidFogSettings);
@@ -125,6 +127,7 @@ public class CClient extends ConfigBase {
 				"The sign (-/+) of this value determines what side of the row the button appears on (left/right)"
 		};
 		static String ignoreFabulousWarning = "Setting this to true will prevent Create from sending you a warning when playing with Fabulous graphics enabled";
+		static String rotatewhenSeated = "Disable to prevent being rotated while seated on a Moving Contraption";
 		static String overlay = "Settings for the Goggle Overlay";
 		static String overlayOffset = "Offset the overlay from goggle- and hover- information by this many pixels on the respective axis; Use /create overlay";
 		static String overlayCustomColor = "Enable this to use your custom colors for the Goggle- and Hover- Overlay";