diff --git a/Geometry/MeshPart.cs b/Geometry/MeshPart.cs
index f2eac05..c8d033b 100644
--- a/Geometry/MeshPart.cs
+++ b/Geometry/MeshPart.cs
@@ -3,7 +3,7 @@ using Microsoft.Xna.Framework.Graphics;
 
 namespace Kav
 {
-    public class MeshPart : IIndexDrawable, IGBufferDrawable
+    public class MeshPart : IIndexDrawable, IGBufferDrawable, ICullable
     {
         public IndexBuffer IndexBuffer { get; }
         public VertexBuffer VertexBuffer { get; }
diff --git a/Renderer.cs b/Renderer.cs
index 45afee8..1fe0b9c 100644
--- a/Renderer.cs
+++ b/Renderer.cs
@@ -8,7 +8,7 @@ namespace Kav
 {
     public class Renderer
     {
-        private const int MAX_INSTANCE_VERTEX_COUNT = 1000;
+        private const int MAX_INSTANCE_VERTEX_COUNT = 1000000;
         private const int MAX_SHADOW_CASCADES = 4;
         private int ShadowMapSize { get; }
 
@@ -314,9 +314,10 @@ namespace Kav
             RenderTargetBinding[] gBuffer,
             PerspectiveCamera camera,
             T drawable,
-            int numInstances,
             IEnumerable<Matrix> transforms
-        ) where T : IIndexDrawable, IGBufferDrawable {
+        ) where T : ICullable, IIndexDrawable, IGBufferDrawable {
+            int numInstances = 0;
+
             GraphicsDevice.SetRenderTargets(gBuffer);
             GraphicsDevice.DepthStencilState = DepthStencilState.Default;
             GraphicsDevice.BlendState = BlendState.Opaque;
@@ -334,12 +335,13 @@ namespace Kav
             Deferred_GBufferEffect.View = camera.View;
             Deferred_GBufferEffect.Projection = camera.Projection;
 
-            int i = 0;
-            foreach (var transform in transforms)
+            var boundingFrustum = new BoundingFrustum(camera.View * camera.Projection);
+
+            foreach (var transform in FrustumCull(boundingFrustum, drawable, transforms))
             {
-                if (i >= numInstances) { break; }
-                GBufferInstanceVertices[i].World = transform;
-                i += 1;
+
+                GBufferInstanceVertices[numInstances].World = transform;
+                numInstances += 1;
             }
 
             GBufferInstanceVertexBuffer.SetData(
@@ -824,6 +826,23 @@ namespace Kav
             }
         }
 
+        private static IEnumerable<Matrix> FrustumCull<T>(
+            BoundingFrustum boundingFrustum,
+            T cullable,
+            IEnumerable<Matrix> transforms
+        ) where T : ICullable
+        {
+            foreach (var transform in transforms)
+            {
+                var boundingBox = TransformedBoundingBox(cullable.BoundingBox, transform);
+                var containment = boundingFrustum.Contains(boundingBox);
+                if (containment != ContainmentType.Disjoint)
+                {
+                    yield return transform;
+                }
+            }
+        }
+
         private static BoundingBox TransformedBoundingBox(BoundingBox boundingBox, Matrix matrix)
         {
             var center = (boundingBox.Min + boundingBox.Max) / 2f;