Fix arms glitching out on contraptions.

- Also provide a hook for subclasses of InstancedTileRenderer to control when specific instances tick.

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

@@ -57,6 +57,11 @@ public class ContraptionKineticRenderer extends InstancedTileRenderer<Contraptio
         actors.forEach(ActorInstance::beginFrame);
     }
 
+    @Override
+    protected boolean shouldTick(BlockPos worldPos, float lookX, float lookY, float lookZ, int cX, int cY, int cZ) {
+        return true;
+    }
+
     @Nullable
     public ActorInstance createActor(Pair<Template.BlockInfo, MovementContext> actor) {
         Template.BlockInfo blockInfo = actor.getLeft();

src/main/java/com/simibubi/create/content/logistics/block/mechanicalArm/ArmTileEntity.java

@@ -79,13 +79,13 @@ public class ArmTileEntity extends KineticTileEntity {
 		phase = Phase.SEARCH_INPUTS;
 		previousTarget = ArmAngleTarget.NO_TARGET;
 		baseAngle = new InterpolatedAngle();
-		baseAngle.set(previousTarget.baseAngle);
+		baseAngle.init(previousTarget.baseAngle);
 		lowerArmAngle = new InterpolatedAngle();
-		lowerArmAngle.set(previousTarget.lowerArmAngle);
+		lowerArmAngle.init(previousTarget.lowerArmAngle);
 		upperArmAngle = new InterpolatedAngle();
-		upperArmAngle.set(previousTarget.upperArmAngle);
+		upperArmAngle.init(previousTarget.upperArmAngle);
 		headAngle = new InterpolatedAngle();
-		headAngle.set(previousTarget.headAngle);
+		headAngle.init(previousTarget.headAngle);
 		clawAngle = new InterpolatedAngle();
 		previousBaseAngle = previousTarget.baseAngle;
 		updateInteractionPoints = true;

src/main/java/com/simibubi/create/foundation/gui/widgets/InterpolatedValue.java

@@ -12,6 +12,11 @@ public class InterpolatedValue {
 		this.value = value;
 		return this;
 	}
+
+	public InterpolatedValue init(float value) {
+		this.lastValue = this.value = value;
+		return this;
+	}
 	
 	public float get(float partialTicks) {
 		return MathHelper.lerp(partialTicks, lastValue, value);

src/main/java/com/simibubi/create/foundation/render/backend/instancing/InstancedTileRenderer.java

@@ -57,11 +57,7 @@ public abstract class InstancedTileRenderer<P extends BasicProgram> {
                 int dY = pos.getY() - cY;
                 int dZ = pos.getZ() - cZ;
 
-                int dSq = dX * dX + dY * dY + dZ * dZ;
+                if ((frame % getUpdateDivisor(dX, dY, dZ)) == 0)
-
-                int divisor = (dSq / 1024) + 1;
-
-                if (frame % divisor == 0)
                     instance.tick();
             }
         }
@@ -88,21 +84,7 @@ public abstract class InstancedTileRenderer<P extends BasicProgram> {
                     continue;
                 }
 
-                BlockPos pos = dyn.getWorldPosition();
+                if (shouldTick(dyn.getWorldPosition(), lookX, lookY, lookZ, cX, cY, cZ))
-
-                int dX = pos.getX() - cX;
-                int dY = pos.getY() - cY;
-                int dZ = pos.getZ() - cZ;
-
-                float dot = dX * lookX + dY * lookY + dZ * lookZ;
-
-                if (dot < 0) continue; // is it behind the camera?
-
-                int dSq = dX * dX + dY * dY + dZ * dZ;
-
-                int divisor = (dSq / 1024) + 1; // https://www.desmos.com/calculator/aaycpludsy
-
-                if (frame % divisor == 0)
                     dyn.beginFrame();
             }
         }
@@ -207,6 +189,24 @@ public abstract class InstancedTileRenderer<P extends BasicProgram> {
         }
     }
 
+    protected boolean shouldTick(BlockPos worldPos, float lookX, float lookY, float lookZ, int cX, int cY, int cZ) {
+        int dX = worldPos.getX() - cX;
+        int dY = worldPos.getY() - cY;
+        int dZ = worldPos.getZ() - cZ;
+
+        float dot = dX * lookX + dY * lookY + dZ * lookZ;
+
+        if (dot < 0) return false; // is it behind the camera?
+
+        return (frame % getUpdateDivisor(dX, dY, dZ)) == 0;
+    }
+
+    protected int getUpdateDivisor(int dX, int dY, int dZ) {
+        int dSq = dX * dX + dY * dY + dZ * dZ;
+
+        return (dSq / 1024) + 1;
+    }
+
     private void addInternal(TileEntity tile) {
         getInstance(tile, true);
     }