diff --git a/engine/rend/shaders/lit_mesh.frag.hlsl b/engine/rend/shaders/lit_mesh.frag.hlsl
index fdcc1e2..ec0888f 100644
--- a/engine/rend/shaders/lit_mesh.frag.hlsl
+++ b/engine/rend/shaders/lit_mesh.frag.hlsl
@@ -59,9 +59,11 @@ float4 main(
     float3 Normal: TEXCOORD2
 ) : SV_Target0
 {
+
     float3 lightPos = float3(0, 20 + -4, -5);
     float3 lightColor = float3(0.8, 0.8, 0.5);
-    float3 ambient = float3(0.01, 0.01, 0.003) * 0.2;
+
+    float3 ambient = lerp(float3(0.01, 0.01, 0.003), float3(0.004, 0.004, 0.06), dot(Normal, float3(0.0,1.0,0.0)) );
 
     float4 s = Texture.Sample(Sampler, UV);
     float alpha = s.w;
diff --git a/engine/rend/src/sgpu/DebugDrawSystem.zig b/engine/rend/src/sgpu/DebugDrawSystem.zig
new file mode 100644
index 0000000..371baad
--- /dev/null
+++ b/engine/rend/src/sgpu/DebugDrawSystem.zig
@@ -0,0 +1,98 @@
+pub var NeonObjectTable: core.EngineObjectVTable = core.EngineObjectVTable.from(@This());
+
+allocator: std.mem.Allocator,
+device: *gpu.GPUDevice = undefined,
+
+const assetReferences = [_]assets.AssetImportReference{
+    assets.MakeImportRefOptions(
+        "Mesh",
+        "m_debug_box",
+        .{ .path = "embedded:debug_box.obj" },
+    ),
+    assets.MakeImportRefOptions(
+        "Mesh",
+        "m_debug_line",
+        .{ .path = "embedded:debug_line.obj" },
+    ),
+    assets.MakeImportRefOptions(
+        "Mesh",
+        "m_debug_sphere",
+        .{ .path = "embedded:debug_sphere.obj" },
+    ),
+};
+
+pub fn create(allocator: std.mem.Allocator) !*@This() {
+    const self = try allocator.create(@This());
+    self.* = .{
+        .allocator = allocator,
+    };
+    core.engine_logs("[DebugDrawSystem] starting up...");
+
+    _ = try core.fs().installFileBytesMount("embedded:debug_box.obj", @constCast(&primitive_box), true);
+    _ = try core.fs().installFileBytesMount("embedded:debug_line.obj", @constCast(&primitive_line), true);
+    _ = try core.fs().installFileBytesMount("embedded:debug_sphere.obj", @constCast(&primitive_sphere), true);
+
+    try assets.loadList(assetReferences);
+
+    return self;
+}
+
+pub fn setup(self: *@This(), device: *gpu.GPUDevice) !void {
+    self.device = device;
+}
+
+pub fn destroy(self: *@This()) void {
+    self.allocator.destroy(self);
+}
+
+pub fn debugSphere(position: core.Vectorf, radius: f32, params: DebugDrawParams) void {
+    _ = position;
+    _ = radius;
+    _ = params;
+    // gDebugDrawSys.debugDraws.push(.{
+    //     .primitive = .{ .sphere = .{ .position = position, .radius = radius, .rotation = params.rotation } },
+    //     .color = params.color,
+    //     .duration = params.duration,
+    // }) catch return;
+}
+
+pub fn debugLine(start: core.Vectorf, end: core.Vectorf, params: DebugDrawParams) void {
+    _ = start;
+    _ = end;
+    _ = params;
+    // gDebugDrawSys.debugDraws.push(.{
+    //     .primitive = .{ .line = .{
+    //         .start = start,
+    //         .end = end,
+    //     } },
+    //     .color = params.color,
+    //     .duration = params.duration,
+    // }) catch return;
+}
+
+pub fn debugBox(position: core.Vectorf, extents: core.Vectorf, params: DebugDrawParams) void {
+    _ = position;
+    _ = extents;
+    _ = params;
+    // gDebugDrawSys.debugDraws.push(.{
+    //     .primitive = .{
+    //         .box = .{ .position = position, .extents = extents, .rotation = params.rotation },
+    //     },
+    //     .color = params.color,
+    //     .duration = params.duration,
+    // }) catch return;
+}
+
+const DebugDrawParams = core.DebugDrawParams;
+
+const core = @import("core");
+const rend = @import("../rend.zig");
+const assets = @import("assets");
+const texture = rend.texture;
+const sdl3 = @import("sdl3");
+const gpu = sdl3.gpu;
+const std = @import("std");
+
+const primitive_box align(8) = @embedFile("embedded/primitive_box.obj").*;
+const primitive_line align(8) = @embedFile("embedded/primitive_line.obj").*;
+const primitive_sphere align(8) = @embedFile("embedded/primitive_sphere.obj").*;
diff --git a/engine/rend/src/sgpu/embedded/primitive_box.obj b/engine/rend/src/sgpu/embedded/primitive_box.obj
new file mode 100644
index 0000000..a23b13b
--- /dev/null
+++ b/engine/rend/src/sgpu/embedded/primitive_box.obj
@@ -0,0 +1,40 @@
+# Blender v3.1.2 OBJ File: ''
+# www.blender.org
+mtllib primitive_box.mtl
+o Cube
+v 1.000000 1.000000 -1.000000
+v 1.000000 -1.000000 -1.000000
+v 1.000000 1.000000 1.000000
+v 1.000000 -1.000000 1.000000
+v -1.000000 1.000000 -1.000000
+v -1.000000 -1.000000 -1.000000
+v -1.000000 1.000000 1.000000
+v -1.000000 -1.000000 1.000000
+vt 0.625000 0.500000
+vt 0.875000 0.500000
+vt 0.875000 0.750000
+vt 0.625000 0.750000
+vt 0.375000 0.750000
+vt 0.625000 1.000000
+vt 0.375000 1.000000
+vt 0.375000 0.000000
+vt 0.625000 0.000000
+vt 0.625000 0.250000
+vt 0.375000 0.250000
+vt 0.125000 0.500000
+vt 0.375000 0.500000
+vt 0.125000 0.750000
+vn 0.0000 1.0000 0.0000
+vn 0.0000 0.0000 1.0000
+vn -1.0000 0.0000 0.0000
+vn 0.0000 -1.0000 0.0000
+vn 1.0000 0.0000 0.0000
+vn 0.0000 0.0000 -1.0000
+usemtl Material
+s off
+f 1/1/1 5/2/1 7/3/1 3/4/1
+f 4/5/2 3/4/2 7/6/2 8/7/2
+f 8/8/3 7/9/3 5/10/3 6/11/3
+f 6/12/4 2/13/4 4/5/4 8/14/4
+f 2/13/5 1/1/5 3/4/5 4/5/5
+f 6/11/6 5/10/6 1/1/6 2/13/6
diff --git a/engine/rend/src/sgpu/embedded/primitive_line.obj b/engine/rend/src/sgpu/embedded/primitive_line.obj
new file mode 100644
index 0000000..e9c3ea3
--- /dev/null
+++ b/engine/rend/src/sgpu/embedded/primitive_line.obj
@@ -0,0 +1,14 @@
+# Blender v3.1.2 OBJ File: ''
+# www.blender.org
+mtllib primitive_line.mtl
+o Plane
+v 1.000000 -0.000001 -0.000001
+v -0.000000 0.000001 0.000000
+v 1.000000 -0.000001 -0.000001
+vt 0.000000 0.000000
+vt 0.000000 0.000000
+vt 0.000000 0.000000
+vn 0.0000 0.0000 1.0000
+usemtl None
+s off
+f 2/1/1 3/2/1 1/3/1
diff --git a/engine/rend/src/sgpu/embedded/primitive_sphere.obj b/engine/rend/src/sgpu/embedded/primitive_sphere.obj
new file mode 100644
index 0000000..1e50f95
--- /dev/null
+++ b/engine/rend/src/sgpu/embedded/primitive_sphere.obj
@@ -0,0 +1,271 @@
+# Blender v3.1.2 OBJ File: ''
+# www.blender.org
+mtllib primitive_sphere.mtl
+o Sphere
+v 0.000000 0.923880 -0.382683
+v 0.000000 0.707107 -0.707107
+v 0.000000 0.382683 -0.923880
+v 0.000000 -0.000000 -1.000000
+v 0.000000 -0.382683 -0.923880
+v 0.000000 -0.707107 -0.707107
+v 0.000000 -0.923880 -0.382683
+v 0.270598 0.923880 -0.270598
+v 0.500000 0.707107 -0.500000
+v 0.653282 0.382683 -0.653281
+v 0.707107 -0.000000 -0.707107
+v 0.653282 -0.382683 -0.653282
+v 0.500000 -0.707107 -0.500000
+v 0.270598 -0.923880 -0.270598
+v 0.382684 0.923880 0.000000
+v 0.707107 0.707107 0.000000
+v 0.923880 0.382683 0.000000
+v 1.000000 -0.000000 0.000000
+v 0.923880 -0.382683 0.000000
+v 0.707107 -0.707107 0.000000
+v 0.382684 -0.923880 0.000000
+v 0.270598 0.923880 0.270598
+v 0.500000 0.707107 0.500000
+v 0.653282 0.382683 0.653282
+v 0.707107 -0.000000 0.707107
+v 0.653282 -0.382683 0.653282
+v 0.500000 -0.707107 0.500000
+v 0.270598 -0.923880 0.270598
+v 0.000000 0.923880 0.382684
+v 0.000000 0.707107 0.707107
+v 0.000000 0.382683 0.923880
+v 0.000000 -0.000000 1.000000
+v 0.000000 -0.382683 0.923880
+v 0.000000 -0.707107 0.707107
+v 0.000000 -0.923880 0.382684
+v -0.000000 1.000000 0.000000
+v -0.270598 0.923880 0.270598
+v -0.500000 0.707107 0.500000
+v -0.653281 0.382683 0.653282
+v -0.707107 -0.000000 0.707107
+v -0.653282 -0.382683 0.653282
+v -0.500000 -0.707107 0.500000
+v -0.270598 -0.923880 0.270598
+v -0.382684 0.923880 0.000000
+v -0.707107 0.707107 0.000000
+v -0.923879 0.382683 0.000000
+v -1.000000 -0.000000 0.000000
+v -0.923880 -0.382683 0.000000
+v -0.707107 -0.707107 0.000000
+v -0.382684 -0.923880 0.000000
+v 0.000000 -1.000000 0.000000
+v -0.270598 0.923880 -0.270598
+v -0.500000 0.707107 -0.500000
+v -0.653281 0.382683 -0.653281
+v -0.707107 -0.000000 -0.707107
+v -0.653282 -0.382683 -0.653281
+v -0.500000 -0.707107 -0.500000
+v -0.270598 -0.923880 -0.270598
+vt 0.750000 0.375000
+vt 0.750000 0.500000
+vt 0.625000 0.500000
+vt 0.625000 0.375000
+vt 0.750000 0.625000
+vt 0.750000 0.750000
+vt 0.625000 0.750000
+vt 0.625000 0.625000
+vt 0.750000 0.875000
+vt 0.687500 1.000000
+vt 0.625000 0.875000
+vt 0.687500 0.000000
+vt 0.750000 0.125000
+vt 0.625000 0.125000
+vt 0.750000 0.250000
+vt 0.625000 0.250000
+vt 0.562500 0.000000
+vt 0.500000 0.125000
+vt 0.500000 0.375000
+vt 0.500000 0.250000
+vt 0.500000 0.625000
+vt 0.500000 0.500000
+vt 0.500000 0.875000
+vt 0.500000 0.750000
+vt 0.562500 1.000000
+vt 0.375000 0.875000
+vt 0.375000 0.750000
+vt 0.375000 0.250000
+vt 0.375000 0.125000
+vt 0.375000 0.500000
+vt 0.375000 0.375000
+vt 0.375000 0.625000
+vt 0.437500 1.000000
+vt 0.437500 0.000000
+vt 0.250000 0.250000
+vt 0.250000 0.125000
+vt 0.250000 0.500000
+vt 0.250000 0.375000
+vt 0.250000 0.750000
+vt 0.250000 0.625000
+vt 0.312500 1.000000
+vt 0.250000 0.875000
+vt 0.312500 0.000000
+vt 0.187500 1.000000
+vt 0.125000 0.875000
+vt 0.187500 0.000000
+vt 0.125000 0.125000
+vt 0.125000 0.375000
+vt 0.125000 0.250000
+vt 0.125000 0.625000
+vt 0.125000 0.500000
+vt 0.125000 0.750000
+vt 0.000000 0.375000
+vt 0.000000 0.250000
+vt 0.000000 0.625000
+vt 0.000000 0.500000
+vt 0.000000 0.875000
+vt 0.000000 0.750000
+vt 0.000000 0.125000
+vt 0.062500 1.000000
+vt 0.062500 0.000000
+vt 1.000000 0.125000
+vt 1.000000 0.250000
+vt 0.875000 0.250000
+vt 0.875000 0.125000
+vt 1.000000 0.375000
+vt 1.000000 0.500000
+vt 0.875000 0.500000
+vt 0.875000 0.375000
+vt 1.000000 0.625000
+vt 1.000000 0.750000
+vt 0.875000 0.750000
+vt 0.875000 0.625000
+vt 1.000000 0.875000
+vt 0.937500 1.000000
+vt 0.875000 0.875000
+vt 0.937500 0.000000
+vt 0.812500 1.000000
+vt 0.812500 0.000000
+vn 0.3764 -0.1807 -0.9087
+vn 0.3256 0.5253 -0.7862
+vn 0.0805 0.9776 -0.1945
+vn 0.0805 -0.9776 -0.1945
+vn 0.3256 -0.5253 -0.7862
+vn 0.3764 0.1807 -0.9087
+vn 0.2243 0.8103 -0.5414
+vn 0.2243 -0.8103 -0.5414
+vn 0.1945 -0.9776 -0.0805
+vn 0.7862 -0.5253 -0.3256
+vn 0.9087 0.1807 -0.3764
+vn 0.5414 0.8103 -0.2243
+vn 0.5414 -0.8103 -0.2243
+vn 0.9087 -0.1807 -0.3764
+vn 0.7862 0.5253 -0.3256
+vn 0.1945 0.9776 -0.0805
+vn 0.5414 0.8103 0.2243
+vn 0.5414 -0.8103 0.2243
+vn 0.9087 -0.1807 0.3764
+vn 0.7862 0.5253 0.3256
+vn 0.1945 0.9776 0.0805
+vn 0.1945 -0.9776 0.0805
+vn 0.7862 -0.5253 0.3256
+vn 0.9087 0.1807 0.3764
+vn 0.2243 -0.8103 0.5414
+vn 0.3764 -0.1807 0.9087
+vn 0.3256 0.5253 0.7862
+vn 0.0805 0.9776 0.1945
+vn 0.0805 -0.9776 0.1945
+vn 0.3256 -0.5253 0.7862
+vn 0.3764 0.1807 0.9087
+vn 0.2243 0.8103 0.5414
+vn -0.0805 0.9776 0.1945
+vn -0.0805 -0.9776 0.1945
+vn -0.3256 -0.5253 0.7862
+vn -0.3764 0.1807 0.9087
+vn -0.2243 0.8103 0.5414
+vn -0.2243 -0.8103 0.5414
+vn -0.3764 -0.1807 0.9087
+vn -0.3256 0.5253 0.7862
+vn -0.7862 -0.5253 0.3256
+vn -0.9087 0.1807 0.3764
+vn -0.5414 0.8103 0.2243
+vn -0.5414 -0.8103 0.2243
+vn -0.9087 -0.1807 0.3764
+vn -0.7862 0.5253 0.3256
+vn -0.1945 0.9776 0.0805
+vn -0.1945 -0.9776 0.0805
+vn -0.5414 -0.8103 -0.2243
+vn -0.9087 -0.1807 -0.3764
+vn -0.7862 0.5253 -0.3256
+vn -0.1945 0.9776 -0.0805
+vn -0.1945 -0.9776 -0.0805
+vn -0.7862 -0.5253 -0.3256
+vn -0.9087 0.1807 -0.3764
+vn -0.5414 0.8103 -0.2243
+vn -0.3764 -0.1807 -0.9087
+vn -0.3256 0.5253 -0.7862
+vn -0.0805 0.9776 -0.1945
+vn -0.0805 -0.9776 -0.1945
+vn -0.3256 -0.5253 -0.7862
+vn -0.3764 0.1807 -0.9087
+vn -0.2243 0.8103 -0.5414
+vn -0.2243 -0.8103 -0.5414
+usemtl None
+s off
+f 5/1/1 4/2/1 11/3/1 12/4/1
+f 3/5/2 2/6/2 9/7/2 10/8/2
+f 1/9/3 36/10/3 8/11/3
+f 51/12/4 7/13/4 14/14/4
+f 6/15/5 5/1/5 12/4/5 13/16/5
+f 4/2/6 3/5/6 10/8/6 11/3/6
+f 2/6/7 1/9/7 8/11/7 9/7/7
+f 7/13/8 6/15/8 13/16/8 14/14/8
+f 51/17/9 14/14/9 21/18/9
+f 13/16/10 12/4/10 19/19/10 20/20/10
+f 11/3/11 10/8/11 17/21/11 18/22/11
+f 9/7/12 8/11/12 15/23/12 16/24/12
+f 14/14/13 13/16/13 20/20/13 21/18/13
+f 12/4/14 11/3/14 18/22/14 19/19/14
+f 10/8/15 9/7/15 16/24/15 17/21/15
+f 8/11/16 36/25/16 15/23/16
+f 16/24/17 15/23/17 22/26/17 23/27/17
+f 21/18/18 20/20/18 27/28/18 28/29/18
+f 19/19/19 18/22/19 25/30/19 26/31/19
+f 17/21/20 16/24/20 23/27/20 24/32/20
+f 15/23/21 36/33/21 22/26/21
+f 51/34/22 21/18/22 28/29/22
+f 20/20/23 19/19/23 26/31/23 27/28/23
+f 18/22/24 17/21/24 24/32/24 25/30/24
+f 28/29/25 27/28/25 34/35/25 35/36/25
+f 26/31/26 25/30/26 32/37/26 33/38/26
+f 24/32/27 23/27/27 30/39/27 31/40/27
+f 22/26/28 36/41/28 29/42/28
+f 51/43/29 28/29/29 35/36/29
+f 27/28/30 26/31/30 33/38/30 34/35/30
+f 25/30/31 24/32/31 31/40/31 32/37/31
+f 23/27/32 22/26/32 29/42/32 30/39/32
+f 29/42/33 36/44/33 37/45/33
+f 51/46/34 35/36/34 43/47/34
+f 34/35/35 33/38/35 41/48/35 42/49/35
+f 32/37/36 31/40/36 39/50/36 40/51/36
+f 30/39/37 29/42/37 37/45/37 38/52/37
+f 35/36/38 34/35/38 42/49/38 43/47/38
+f 33/38/39 32/37/39 40/51/39 41/48/39
+f 31/40/40 30/39/40 38/52/40 39/50/40
+f 42/49/41 41/48/41 48/53/41 49/54/41
+f 40/51/42 39/50/42 46/55/42 47/56/42
+f 38/52/43 37/45/43 44/57/43 45/58/43
+f 43/47/44 42/49/44 49/54/44 50/59/44
+f 41/48/45 40/51/45 47/56/45 48/53/45
+f 39/50/46 38/52/46 45/58/46 46/55/46
+f 37/45/47 36/60/47 44/57/47
+f 51/61/48 43/47/48 50/59/48
+f 50/62/49 49/63/49 57/64/49 58/65/49
+f 48/66/50 47/67/50 55/68/50 56/69/50
+f 46/70/51 45/71/51 53/72/51 54/73/51
+f 44/74/52 36/75/52 52/76/52
+f 51/77/53 50/62/53 58/65/53
+f 49/63/54 48/66/54 56/69/54 57/64/54
+f 47/67/55 46/70/55 54/73/55 55/68/55
+f 45/71/56 44/74/56 52/76/56 53/72/56
+f 56/69/57 55/68/57 4/2/57 5/1/57
+f 54/73/58 53/72/58 2/6/58 3/5/58
+f 52/76/59 36/78/59 1/9/59
+f 51/79/60 58/65/60 7/13/60
+f 57/64/61 56/69/61 5/1/61 6/15/61
+f 55/68/62 54/73/62 3/5/62 4/2/62
+f 53/72/63 52/76/63 1/9/63 2/6/63
+f 58/65/64 57/64/64 6/15/64 7/13/64
diff --git a/engine/rend/src/sgpu/renderer.zig b/engine/rend/src/sgpu/renderer.zig
index 15afa91..2ed8dbc 100644
--- a/engine/rend/src/sgpu/renderer.zig
+++ b/engine/rend/src/sgpu/renderer.zig
@@ -40,12 +40,13 @@ pub const Renderer = struct {
     textureList: *TextureList = undefined,
 
     blockySampler: *gpu.GPUSampler = undefined,
+    defaultTexture: *rend.Texture = undefined,
+
+    debugDrawSys: *DebugDrawSystem = undefined,
 
     // transients DO NOT TOUCH
     swapchainTexture: *gpu.GPUTexture = undefined,
 
-    defaultTexture: *rend.Texture = undefined,
-
     pub var NeonObjectTable: core.EngineObjectVTable = core.EngineObjectVTable.from(@This());
 
     pub const MaxObjectCount = 50000;
@@ -106,6 +107,8 @@ pub const Renderer = struct {
 
         var defaultTextureName = core.MakeName("t_default");
         self.defaultTexture = getTexture(&defaultTextureName).?;
+
+        self.debugDrawSys = try core.createObject(DebugDrawSystem, .{});
     }
 
     pub fn createSamplers(self: *@This()) !void {
@@ -549,6 +552,8 @@ pub const MeshPool = mesh_pool.MeshPool;
 
 pub const TextureList = @import("TextureList.zig");
 
+const DebugDrawSystem = @import("DebugDrawSystem.zig");
+
 // debug api
 
 pub fn reloadShaders() !void {
diff --git a/lib/packer/src/packerfs.zig b/lib/packer/src/packerfs.zig
index e98d14b..3d80af3 100644
--- a/lib/packer/src/packerfs.zig
+++ b/lib/packer/src/packerfs.zig
@@ -74,12 +74,19 @@ pub const PackerFS = struct {
         mountRefs: std.ArrayListUnmanaged(usize) = .{},
         contentOffset: usize = 0,
         inMemory: bool = false,
+        embedded: bool = false,
 
         pub fn isFileMounted(self: @This()) bool {
-            return self.mounted;
+            return self.mounted or self.embedded;
         }
 
         pub fn unmount(self: *@This(), allocator: std.mem.Allocator) void {
+            if (self.embedded) {
+                self.mountRefs.deinit(allocator);
+                self.mountRefs = .{};
+                return;
+            }
+
             if (self.mounted) {
                 // std.debug.print("unmounting file:{s} bytes: 0x{x}\n", .{ self.filePath, @intFromPtr(self.bytes.ptr) });
                 allocator.free(self.bytes);
@@ -90,6 +97,9 @@ pub const PackerFS = struct {
         }
 
         pub fn removeMapping(self: *@This(), allocator: std.mem.Allocator, fileRef: usize) void {
+            if (self.embedded)
+                return;
+
             for (0..self.mountRefs.items.len) |i| {
                 if (self.mountRefs.items[i] == fileRef) {
                     _ = self.mountRefs.swapRemove(i);
@@ -237,6 +247,10 @@ pub const PackerFS = struct {
             },
         });
 
+        return try self.installFileBytesMount(fullPath, fileBytes, false);
+    }
+
+    pub fn installFileBytesMount(self: *@This(), path: []const u8, fileBytes: []align(8) u8, embedded: bool) !?PackerBytesMapping {
         const pakMountIndex = self.pakMountings.items.len;
         try self.pakMountings.append(self.allocator, .{
             .filePath = try self.stringAlloc().dupe(u8, path),
@@ -252,6 +266,7 @@ pub const PackerFS = struct {
         self.pakMountings.items[pakMountIndex].bytes = fileBytes;
         try self.pakMountings.items[pakMountIndex].mountRefs.append(self.allocator, headerIndex);
         self.pakMountings.items[pakMountIndex].mounted = true;
+        self.pakMountings.items[pakMountIndex].embedded = embedded;
 
         // std.debug.print("loadFileDirect {s} {d} 0x{x}\n", .{ path, headerIndex, @intFromPtr(fileBytes.ptr) });
         return .{