Make the interpolatorId private

src/main/java/com/minelittlepony/api/model/ModelAttributes.java

@@ -1,8 +1,10 @@
 package com.minelittlepony.api.model;
 
 import com.minelittlepony.api.pony.*;
+import com.minelittlepony.client.IPreviewModel;
 import com.minelittlepony.client.SkinsProxy;
 import com.minelittlepony.client.pony.PonyData;
+import com.minelittlepony.common.util.animation.Interpolator;
 import com.minelittlepony.util.MathUtil;
 
 import java.util.*;
@@ -82,7 +84,7 @@ public class ModelAttributes {
      * Unique id of the interpolator used for this model.
      * Usually the UUID of the entity being rendered.
      */
-    public UUID interpolatorId = UUID.randomUUID();
+    private UUID interpolatorId = UUID.randomUUID();
 
     /**
      * The actual, visible height of this model when rendered.
@@ -150,6 +152,10 @@ public class ModelAttributes {
         featureSkins = SkinsProxy.instance.getAvailableSkins(entity);
     }
 
+    public Interpolator getMainInterpolator() {
+        return metadata.getInterpolator(interpolatorId);
+    }
+
     public boolean shouldLiftArm(ArmPose pose, ArmPose complement, float sigma) {
         return pose != ArmPose.EMPTY
                 && (pose != complement || sigma == (isLeftHanded ? 1 : -1))

src/main/java/com/minelittlepony/client/model/AbstractPonyModel.java

@@ -122,7 +122,7 @@ public abstract class AbstractPonyModel<T extends LivingEntity> extends ClientPo
         float pitch = (float)Math.toRadians(attributes.motionPitch);
         head.setAngles(
                 MathHelper.clamp(attributes.isSleeping ? 0.1f : headPitch / 57.29578F, -1.25f - pitch, 0.5f - pitch),
-                attributes.isSleeping ? (Math.abs(attributes.interpolatorId.getMostSignificantBits()) % 2.8F) - 1.9F : headYaw / 57.29578F,
+                attributes.isSleeping ? (Math.abs(entity.getUuid().getMostSignificantBits()) % 2.8F) - 1.9F : headYaw / 57.29578F,
                 0
         );
 
@@ -274,7 +274,7 @@ public abstract class AbstractPonyModel<T extends LivingEntity> extends ClientPo
         rightArm.pivotZ = 2 + sin;
         leftArm.pivotZ = 2 - sin;
 
-        float legRPX = getMetadata().getInterpolator(attributes.interpolatorId).interpolate("legOffset", cos - getLegOutset() - 0.001F, 2);
+        float legRPX = attributes.getMainInterpolator().interpolate("legOffset", cos - getLegOutset() - 0.001F, 2);
 
         rightArm.pivotX = -legRPX;
         rightLeg.pivotX = -legRPX;
@@ -319,7 +319,7 @@ public abstract class AbstractPonyModel<T extends LivingEntity> extends ClientPo
         float baseRotation = move * 0.6662F; // magic number ahoy
         float scale = swing / 4;
 
-        float rainboomLegLotation = getMetadata().getInterpolator(attributes.interpolatorId).interpolate(
+        float rainboomLegLotation = attributes.getMainInterpolator().interpolate(
                 "rainboom_leg_rotation",
                 attributes.isGoingFast ? 1 : 0,
                 5

src/main/java/com/minelittlepony/client/model/part/LionTail.java

@@ -25,7 +25,7 @@ public class LionTail implements IPart {
         float baseSail = 1F;
 
         float speed = swing > 0.01F ? 6 : 90;
-        Interpolator interpolator = Interpolator.linear(attributes.interpolatorId);
+        Interpolator interpolator = attributes.getMainInterpolator();
 
         float straightness = 1.6F * (1 + (float)Math.sin(ticks / speed) / 8F);
         float twist = (float)Math.sin(Math.PI/2F + 2 * ticks / speed) / 16F;

src/main/java/com/minelittlepony/client/model/part/PonyWings.java

@@ -83,7 +83,7 @@ public class PonyWings<T extends Model & IPegasus> implements IPart, MsonModel {
         }
 
         if (!pegasus.isFlying()) {
-            flapAngle = pegasus.getMetadata().getInterpolator(attributes.interpolatorId).interpolate("wingFlap", flapAngle, 10);
+            flapAngle = attributes.getMainInterpolator().interpolate("wingFlap", flapAngle, 10);
         }
 
         getLeft().rotateFlying(flapAngle);

src/main/java/com/minelittlepony/client/transform/PostureFlight.java

@@ -22,7 +22,7 @@ public class PostureFlight extends MotionCompositor implements PonyPosture {
         model.getAttributes().motionPitch = (float)calculateIncline(player, motionX, motionY, motionZ);
         model.getAttributes().motionRoll = (float)calculateRoll(player, motionX * xScale,  motionY, motionZ * xScale);
 
-        model.getAttributes().motionRoll = model.getMetadata().getInterpolator(model.getAttributes().interpolatorId).interpolate("pegasusRoll", model.getAttributes().motionRoll, 10);
+        model.getAttributes().motionRoll = model.getAttributes().getMainInterpolator().interpolate("pegasusRoll", model.getAttributes().motionRoll, 10);
 
         stack.multiply(RotationAxis.POSITIVE_X.rotationDegrees(model.getAttributes().motionPitch));
         stack.multiply(RotationAxis.POSITIVE_Z.rotationDegrees(model.getAttributes().motionRoll));