Fix Rendering Glitches

src/main/java/kamkeel/npcs/client/renderer/RenderAbilityDisc.java

@@ -59,12 +59,17 @@ public class RenderAbilityDisc extends RenderEnergyAbility {
         double motionX = entity.motionX;
         double motionY = entity.motionY;
         double motionZ = entity.motionZ;
-        Vec3 motionVec = Vec3.createVectorHelper(motionX, motionY, motionZ);
+        double speedSq = motionX * motionX + motionY * motionY + motionZ * motionZ;
 
-        float motionYaw = MathUtil.getYaw(motionVec);
-        float motionPitch = MathUtil.getPitch(motionVec);
-        GL11.glRotatef(motionYaw, 0, 1, 0);
-        GL11.glRotatef(motionPitch, 1, 0, 0);
+        // Only apply motion-based facing when speed is meaningful.
+        // Near-zero motion makes atan2 unstable, producing jittery angles.
+        if (speedSq > 0.0001) {
+            Vec3 motionVec = Vec3.createVectorHelper(motionX, motionY, motionZ);
+            float motionYaw = MathUtil.getYaw(motionVec);
+            float motionPitch = MathUtil.getPitch(motionVec);
+            GL11.glRotatef(motionYaw, 0, 1, 0);
+            GL11.glRotatef(motionPitch, 1, 0, 0);
+        }
 
         // Apply Y-axis rotation for spin
         GL11.glRotatef(disc.getInterpolatedRotationY(partialTicks), 0.0f, 1.0f, 0.0f);

src/main/java/kamkeel/npcs/client/renderer/RenderAbilityLaser.java

@@ -23,9 +23,6 @@ public class RenderAbilityLaser extends RenderEnergyAbility {
 
     @Override
     public void doRender(Entity entity, double x, double y, double z, float yaw, float partialTicks) {
-        if (shouldSkipInitialActiveRender(entity)) {
-            return;
-        }
         EntityAbilityLaser laser = (EntityAbilityLaser) entity;
 
         setupRenderState();

src/main/java/kamkeel/npcs/client/renderer/RenderAbilityOrb.java

@@ -46,12 +46,17 @@ public class RenderAbilityOrb extends RenderEnergyAbility {
         double motionX = entity.motionX;
         double motionY = entity.motionY;
         double motionZ = entity.motionZ;
-        Vec3 motionVec = Vec3.createVectorHelper(motionX, motionY, motionZ);
+        double speedSq = motionX * motionX + motionY * motionY + motionZ * motionZ;
 
-        float motionYaw = MathUtil.getYaw(motionVec);
-        float motionPitch = MathUtil.getPitch(motionVec);
-        GL11.glRotatef(motionYaw, 0, 1, 0);
-        GL11.glRotatef(motionPitch, 1, 0, 0);
+        // Only apply motion-based facing when speed is meaningful.
+        // Near-zero motion makes atan2 unstable, producing jittery angles.
+        if (speedSq > 0.0001) {
+            Vec3 motionVec = Vec3.createVectorHelper(motionX, motionY, motionZ);
+            float motionYaw = MathUtil.getYaw(motionVec);
+            float motionPitch = MathUtil.getPitch(motionVec);
+            GL11.glRotatef(motionYaw, 0, 1, 0);
+            GL11.glRotatef(motionPitch, 1, 0, 0);
+        }
 
         // Use entity's interpolated rotation for smooth spinning
         GL11.glRotatef(orb.getInterpolatedRotationX(partialTicks), 1.0f, 0.0f, 0.0f);

src/main/java/kamkeel/npcs/entity/EntityAbilityDisc.java

@@ -39,6 +39,9 @@ public class EntityAbilityDisc extends EntityEnergyProjectile {
     private int returnOwnerNullTicks = 0;
     private boolean vertical = false; // false = horizontal (flat), true = vertical (thin edge forward)
 
+    // Cached travel direction for smooth rendering when motion is near zero
+    private float lastTravelYaw = 0.0f;
+
     // Charging state (disc-specific target sizes)
     private float targetDiscRadius = 1.0f; // Full radius to grow to during charging
     private float targetDiscThickness = 0.2f; // Full thickness to grow to during charging
@@ -60,7 +63,7 @@ public class EntityAbilityDisc extends EntityEnergyProjectile {
         super(world);
 
         // Initialize base properties
-        initProjectile(owner, target, x, y, z, discRadius, display, combat, lightning, lifespan, trajectory);
+        initProjectile(owner, target, x, y, z, 1.0f, display, combat, lightning, lifespan, trajectory);
 
         this.homingData = homing;
 
@@ -316,7 +319,7 @@ public class EntityAbilityDisc extends EntityEnergyProjectile {
         float progress = getChargeProgress();
         this.discRadius = targetDiscRadius * progress;
         this.discThickness = targetDiscThickness * progress;
-        this.size = this.discRadius; // Base size for interpolation
+        this.size = 1.0f; // Size acts as a scaling factor; discRadius handles actual dimensions
 
         Entity owner = getOwnerEntity();
         if (owner instanceof EntityLivingBase) {
@@ -382,14 +385,15 @@ public class EntityAbilityDisc extends EntityEnergyProjectile {
         if (isCharging()) {
             Entity owner = previewMode ? previewOwner : getOwnerEntity();
             if (owner != null) {
-                return owner.rotationYaw;
+                lastTravelYaw = owner.rotationYaw;
+                return lastTravelYaw;
             }
         }
         double speed = Math.sqrt(motionX * motionX + motionZ * motionZ);
         if (speed > 0.001) {
-            return (float) (Math.atan2(-motionX, motionZ) * 180.0 / Math.PI);
+            lastTravelYaw = (float) (Math.atan2(-motionX, motionZ) * 180.0 / Math.PI);
         }
-        return 0.0f;
+        return lastTravelYaw;
     }
 
     // ==================== NBT ====================
@@ -406,6 +410,12 @@ public class EntityAbilityDisc extends EntityEnergyProjectile {
         readChargingNBT(nbt);
         this.targetDiscRadius = nbt.hasKey("TargetDiscRadius") ? nbt.getFloat("TargetDiscRadius") : this.discRadius;
         this.targetDiscThickness = nbt.hasKey("TargetDiscThickness") ? nbt.getFloat("TargetDiscThickness") : this.discThickness;
+
+        // Normalize size to 1.0 (scaling factor) — discRadius handles actual dimensions.
+        // Old saves may have size = discRadius baked in from the quadratic scaling bug.
+        this.size = 1.0f;
+        this.renderCurrentSize = 1.0f;
+        this.prevRenderSize = 1.0f;
     }
 
     @Override

src/main/java/kamkeel/npcs/entity/EntityAbilityLaser.java

@@ -6,6 +6,8 @@ import kamkeel.npcs.controllers.data.ability.data.energy.EnergyDisplayData;
 import kamkeel.npcs.controllers.data.ability.data.energy.EnergyLifespanData;
 import kamkeel.npcs.controllers.data.ability.data.energy.EnergyLightningData;
 import kamkeel.npcs.controllers.data.ability.data.energy.EnergyTrajectoryData;
+import cpw.mods.fml.relauncher.Side;
+import cpw.mods.fml.relauncher.SideOnly;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityLivingBase;
 import net.minecraft.nbt.NBTTagCompound;
@@ -103,6 +105,13 @@ public class EntityAbilityLaser extends EntityEnergyProjectile {
         this.endZ = z;
     }
 
+    @Override
+    @SideOnly(Side.CLIENT)
+    public boolean isInRangeToRenderDist(double distance) {
+        double range = Math.max(128.0D, currentLength * 2.0D + 64.0D);
+        return distance < range * range;
+    }
+
     @Override
     protected void updateRotation() {
         // Laser doesn't rotate
@@ -179,7 +188,13 @@ public class EntityAbilityLaser extends EntityEnergyProjectile {
      */
     private void updateLaserOriginAndDirection() {
         Entity owner = getOwnerEntity();
-        if (owner == null || !(owner instanceof EntityLivingBase)) return;
+        if (owner == null || !(owner instanceof EntityLivingBase)) {
+            // On client, fall back to entity tracker interpolation when owner not loaded
+            if (worldObj != null && worldObj.isRemote) {
+                handleClientInterpolation();
+            }
+            return;
+        }
         EntityLivingBase livingOwner = (EntityLivingBase) owner;
 
         // Use owner look vector (head/eye aim) for direction updates so hit logic matches visuals.

src/main/java/kamkeel/npcs/entity/EntityEnergyProjectile.java

@@ -801,19 +801,21 @@ public abstract class EntityEnergyProjectile extends EntityEnergyAbility {
 
     /**
      * Handle client-side position interpolation.
+     * Only moves position during active interpolation (interpSteps > 0).
+     * Does NOT predict/drift between server updates — the motion values are
+     * derived from correction deltas, not actual entity velocity, so applying
+     * them between updates causes entities to fly off in wrong directions.
+     * This matches vanilla Minecraft behavior for non-player entities.
      */
     protected void handleClientInterpolation() {
         if (this.interpSteps > 0) {
-            // For very slow / stationary projectiles, snap directly to avoid jitter
             double dx = this.interpTargetX - this.posX;
             double dy = this.interpTargetY - this.posY;
             double dz = this.interpTargetZ - this.posZ;
             double distSq = dx * dx + dy * dy + dz * dz;
-            if (distSq < 0.04) {
+
+            if (distSq < 0.0001) {
                 this.setPosition(this.interpTargetX, this.interpTargetY, this.interpTargetZ);
-                this.motionX = this.interpTargetMotionX;
-                this.motionY = this.interpTargetMotionY;
-                this.motionZ = this.interpTargetMotionZ;
                 this.interpSteps = 0;
                 return;
             }
@@ -828,16 +830,6 @@ public abstract class EntityEnergyProjectile extends EntityEnergyAbility {
 
             this.setPosition(newX, newY, newZ);
             this.interpSteps--;
-        } else {
-            // Skip motion application for nearly-stationary projectiles to prevent drift
-            double speedSq = this.motionX * this.motionX + this.motionY * this.motionY + this.motionZ * this.motionZ;
-            if (speedSq < 0.0001) {
-                return;
-            }
-            this.posX += this.motionX;
-            this.posY += this.motionY;
-            this.posZ += this.motionZ;
-            this.setPosition(this.posX, this.posY, this.posZ);
         }
     }
 
@@ -1542,9 +1534,7 @@ public abstract class EntityEnergyProjectile extends EntityEnergyAbility {
     protected void setChargeOrigin(Vec3 pos) {
         if (pos == null) return;
         this.setPosition(pos.xCoord, pos.yCoord, pos.zCoord);
-        this.prevPosX = pos.xCoord;
-        this.prevPosY = pos.yCoord;
-        this.prevPosZ = pos.zCoord;
+        syncPositionState(pos.xCoord, pos.yCoord, pos.zCoord, true);
         this.startX = pos.xCoord;
         this.startY = pos.yCoord;
         this.startZ = pos.zCoord;

src/main/java/kamkeel/npcs/entity/EntityEnergySlicer.java

@@ -24,6 +24,10 @@ public class EntityEnergySlicer extends EntityEnergyProjectile {
     private float sliceWidth = 3.0f;
     private float sliceThickness = 0.15f;
 
+    // Cached travel direction for smooth rendering when motion is near zero
+    private float lastTravelYaw = 0.0f;
+    private float lastTravelPitch = 0.0f;
+
     public EntityEnergySlicer(World world) {
         super(world);
     }
@@ -166,13 +170,16 @@ public class EntityEnergySlicer extends EntityEnergyProjectile {
     public float getTravelYaw() {
         if (isCharging()) {
             Entity owner = previewMode ? previewOwner : getOwnerEntity();
-            if (owner != null) return owner.rotationYaw;
+            if (owner != null) {
+                lastTravelYaw = owner.rotationYaw;
+                return lastTravelYaw;
+            }
         }
         double speed = Math.sqrt(motionX * motionX + motionZ * motionZ);
         if (speed > 0.001) {
-            return (float) (Math.atan2(-motionX, motionZ) * 180.0 / Math.PI);
+            lastTravelYaw = (float) (Math.atan2(-motionX, motionZ) * 180.0 / Math.PI);
         }
-        return 0.0f;
+        return lastTravelYaw;
     }
 
     /**
@@ -181,9 +188,9 @@ public class EntityEnergySlicer extends EntityEnergyProjectile {
     public float getTravelPitch() {
         double horizSpeed = Math.sqrt(motionX * motionX + motionZ * motionZ);
         if (horizSpeed > 0.001 || Math.abs(motionY) > 0.001) {
-            return (float) (-Math.atan2(motionY, horizSpeed) * 180.0 / Math.PI);
+            lastTravelPitch = (float) (-Math.atan2(motionY, horizSpeed) * 180.0 / Math.PI);
         }
-        return 0.0f;
+        return lastTravelPitch;
     }
 
     // ==================== GETTERS ====================