diff --git a/assets/shaders/convert.comp.spv b/assets/shaders/convert.comp.spv
new file mode 100644
index 0000000..eef316d
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diff --git a/assets/shaders/gradient.comp.spv b/assets/shaders/gradient.comp.spv
index 8a334e2..d29c57b 100644
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diff --git a/assets/shaders/gui.frag.spv b/assets/shaders/gui.frag.spv
index 3b9e09f..8a577ba 100644
Binary files a/assets/shaders/gui.frag.spv and b/assets/shaders/gui.frag.spv differ
diff --git a/assets/shaders/gui.vert.spv b/assets/shaders/gui.vert.spv
index 96f037c..7eb8f37 100644
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diff --git a/assets/shaders/pbr.frag.spv b/assets/shaders/pbr.frag.spv
index 50f1403..3b228d4 100644
Binary files a/assets/shaders/pbr.frag.spv and b/assets/shaders/pbr.frag.spv differ
diff --git a/assets/shaders/pbr.vert.spv b/assets/shaders/pbr.vert.spv
index 4733175..8177cce 100644
Binary files a/assets/shaders/pbr.vert.spv and b/assets/shaders/pbr.vert.spv differ
diff --git a/assets/shaders/triangle.frag.spv b/assets/shaders/triangle.frag.spv
index e179e70..c4a1dcf 100644
Binary files a/assets/shaders/triangle.frag.spv and b/assets/shaders/triangle.frag.spv differ
diff --git a/assets/shaders/triangle.vert.spv b/assets/shaders/triangle.vert.spv
index b7669bd..dff15cf 100644
Binary files a/assets/shaders/triangle.vert.spv and b/assets/shaders/triangle.vert.spv differ
diff --git a/src/gears/renderer.d b/src/gears/renderer.d
index 3df9a51..5cf0baf 100644
--- a/src/gears/renderer.d
+++ b/src/gears/renderer.d
@@ -114,20 +114,31 @@ struct ShaderUniforms
 	f32 placeholder;
 }
 
-struct Material
+extern(C) struct Material
 {
+	Vec4 ambient;
+	Vec4 diffuse;
+	Vec4 specular;
 	u32 albedo_texture;
 	u32 ambient_texture;
 	u32 specular_texture;
 	b32 albedo_has_texture;
 	b32 ambient_has_texture;
 	b32 specular_has_texture;
-	Vec4 ambient;
-	Vec4 diffuse;
-	Vec4 specular;
 	f32 shininess = 0.0;
 }
 
+static assert(Material.ambient.offsetof == 0, "ambient offset incorrect");
+static assert(Material.diffuse.offsetof == 16, "ambient offset incorrect");
+static assert(Material.specular.offsetof == 32, "ambient offset incorrect");
+static assert(Material.albedo_texture.offsetof == 48, "ambient offset incorrect");
+static assert(Material.ambient_texture.offsetof == 52, "ambient offset incorrect");
+static assert(Material.specular_texture.offsetof == 56, "ambient offset incorrect");
+static assert(Material.albedo_has_texture.offsetof == 60, "ambient offset incorrect");
+static assert(Material.ambient_has_texture.offsetof == 64, "ambient offset incorrect");
+static assert(Material.specular_has_texture.offsetof == 68, "ambient offset incorrect");
+static assert(Material.shininess.offsetof == 72, "ambient offset incorrect");
+
 struct UIVertex
 {
 	Vec2 p0;
@@ -399,45 +410,47 @@ LoadModel(Renderer* rd, string name)
 		u32 w = m3d.texture[i].w; u32 h = m3d.texture[i].h; u32 ch = m3d.texture[i].f;
 		u8[] tex_data = m3d.texture[i].d[0 .. w * h * ch];
 
+		const(char)[] tex_name = m3d.texture[i].name[0 .. strlen(m3d.texture[i].name)];
 		CreateImageView(&rd.vk, &model.textures[i], w, h, ch, tex_data);
 
 		tex_lookup[i] = Pop(&rd.vk, DT.SampledImage);
 	}
 
+	Material[] mats = AllocArray!(Material)(&rd.temp_arena, m3d.nummaterial);
 	u32[] mat_lookup = AllocArray!(u32)(&rd.temp_arena, m3d.nummaterial);
 	model.materials = AllocArray!(Buffer)(&rd.arena, m3d.nummaterial);
 	foreach(i; 0 .. m3d.nummaterial)
 	{
-		Material mat;
+		const(char)[] mat_name = m3d.material[i].name[0 .. strlen(m3d.material[i].name)];
 
 		foreach(j; 0 .. m3d.material[i].numprop)
 		{
 			switch (m3d.material[i].prop[j].type)
 			{
-			case m3dp_Ka: ConvertColor(&mat.ambient, m3d.material[i].prop[j].value.color); break;
-			case m3dp_Ks: ConvertColor(&mat.specular, m3d.material[i].prop[j].value.color); break;
-			case m3dp_Ns: mat.shininess = m3d.material[i].prop[j].value.fnum; break;
+			case m3dp_Ka: ConvertColor(&mats[i].ambient, m3d.material[i].prop[j].value.color); break;
+			case m3dp_Ks: ConvertColor(&mats[i].specular, m3d.material[i].prop[j].value.color); break;
+			case m3dp_Ns: mats[i].shininess = m3d.material[i].prop[j].value.fnum; break;
 			case m3dp_map_Kd:
 				{
-					mat.albedo_texture = tex_lookup[m3d.material[i].prop[j].value.textureid];
-					mat.albedo_has_texture = true;
+					mats[i].albedo_texture = tex_lookup[m3d.material[i].prop[j].value.textureid];
+					mats[i].albedo_has_texture = true;
 				} break;
 			case m3dp_map_Ka:
 				{
-					mat.ambient_texture = tex_lookup[m3d.material[i].prop[j].value.textureid];
-					mat.ambient_has_texture = true;
+					mats[i].ambient_texture = tex_lookup[m3d.material[i].prop[j].value.textureid];
+					mats[i].ambient_has_texture = true;
 				} break;
 			case m3dp_map_Ks:
 				{
-					mat.specular_texture = tex_lookup[m3d.material[i].prop[j].value.textureid];
-					mat.specular_has_texture = true;
+					mats[i].specular_texture = tex_lookup[m3d.material[i].prop[j].value.textureid];
+					mats[i].specular_has_texture = true;
 				} break;
 			default: break;
 			}
 		}
 
 		CreateBuffer(&rd.vk, &model.materials[i], BT.Uniform, Material.sizeof, false);
-		assert(Transfer(&rd.vk, &model.materials[i], &mat), "LoadModel failure: Transfer error when transferring material");
+		assert(Transfer(&rd.vk, &model.materials[i], &mats[i]), "LoadModel failure: Transfer error when transferring material");
 
 		mat_lookup[i] = Pop(&rd.vk, DT.Material);
 	}
@@ -460,7 +473,7 @@ LoadModel(Renderer* rd, string name)
 	{
 		if (last == u64.max)
 		{
-			model.parts[index].mat = m3d.face[i].materialid != u32.max ? mat_lookup[m3d.face[i].materialid] : 0;
+			model.parts[index].mat = (m3d.face[i].materialid != u32.max) ? mat_lookup[m3d.face[i].materialid] : 0;
 			model.parts[index].offset = 0;
 			last = m3d.face[i].materialid;
 		}
diff --git a/src/gears/vulkan.d b/src/gears/vulkan.d
index 9f08054..61d6ab1 100644
--- a/src/gears/vulkan.d
+++ b/src/gears/vulkan.d
@@ -13,6 +13,7 @@ import renderer;
 import std.math.rounding : Ceil = ceil;
 
 bool g_VLAYER_SUPPORT = false;
+bool g_DEBUG_PRINTF = false;
 
 const FRAME_OVERLAP = 2;
 
@@ -124,6 +125,7 @@ struct Buffer
 {
 	VkBuffer 			buffer;
 	VmaAllocation alloc;
+	u64						size;
 }
 
 struct DescBindings
@@ -403,6 +405,8 @@ CreateBuffer(Vulkan* vk, Buffer* buf, BufferType type, u64 size, bool host_visib
 	VkResult result = vmaCreateBuffer(vk.vma, &buffer_info, &alloc_info, &buf.buffer, &buf.alloc, &vma_info);
 	// TODO: handle errors here then reallocate buffer
 	assert(VkCheck("CreateBuffer failure: vmaCreateBuffer error", result), "CreateBuffer failure");
+
+	buf.size = size;
 }
 
 void
@@ -703,6 +707,12 @@ ImmSubmit(Vulkan* vk, void delegate() fn)
 		success = VkCheck("ImmSubmit failure: vkQueueSubmit2 error", result);
 	}
 
+	if (success)
+	{
+		result = vkWaitForFences(vk.device, 1, &vk.imm_fence, true, 999999999);
+		success = VkCheck("ImmSubmit failure: vkWaitForFences post submission error", result);
+	}
+
 	return success;
 }
 
@@ -1435,7 +1445,7 @@ SetUniform(Vulkan* vk, GlobalUniforms* globals)
 
 	VkDescriptorBufferInfo buffer_info = {
 		buffer: vk.global_buf.buffer,
-		range: VK_WHOLE_SIZE,
+		range: GlobalUniforms.sizeof,
 	};
 
 	VkWriteDescriptorSet write = {
@@ -1739,7 +1749,7 @@ WriteConvDescriptor(Vulkan* vk, Buffer* buf)
 {
 	VkDescriptorBufferInfo buf_info = {
 		buffer: buf.buffer,
-		range: VK_WHOLE_SIZE,
+		range: buf.size,
 	};
 
 	VkWriteDescriptorSet write = {
@@ -1785,7 +1795,7 @@ WriteDescriptors(Vulkan* vk, DescType type, Buffer[] buffers, u32[] indices)
 	foreach(i, buf; buffers)
 	{
 		buffer_info[i].buffer = buf.buffer;
-		buffer_info[i].range = VK_WHOLE_SIZE;
+		buffer_info[i].range = buf.size;
 		
 		writes[i].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
 		writes[i].dstSet = vk.desc_sets[type];
@@ -2800,6 +2810,22 @@ InitInstance(Vulkan* vk)
 		ppEnabledExtensionNames: instance_ext.ptr,
 	};
 
+	VkValidationFeatureEnableEXT validation_enable = VK_VALIDATION_FEATURE_ENABLE_DEBUG_PRINTF_EXT;
+
+	VkValidationFeaturesEXT validation_features = {
+		sType: VK_STRUCTURE_TYPE_VALIDATION_FEATURES_EXT,
+		enabledValidationFeatureCount: 1,
+		pEnabledValidationFeatures: &validation_enable,
+	};
+
+	debug
+	{
+		if (g_VLAYER_SUPPORT && g_DEBUG_PRINTF)
+		{
+			instance_info.pNext = &validation_features;
+		}
+	}
+
 	VkResult result = vkCreateInstance(&instance_info, null, &vk.instance);
 	success = VkCheck("vkCreateInstance failure", result);
 
@@ -2848,14 +2874,19 @@ EnableVLayers(Vulkan* vk)
 		if (g_VLAYER_SUPPORT)
 		{
 			VkDebugUtilsMessengerCreateInfoEXT info = {
-			sType: VK_STRUCTURE_TYPE_DEBUG_UTILS_MESSENGER_CREATE_INFO_EXT,
-			messageSeverity: VK_DEBUG_UTILS_MESSAGE_SEVERITY_WARNING_BIT_EXT |
-											 VK_DEBUG_UTILS_MESSAGE_SEVERITY_ERROR_BIT_EXT,
-			messageType: VK_DEBUG_UTILS_MESSAGE_TYPE_GENERAL_BIT_EXT		|
-									 VK_DEBUG_UTILS_MESSAGE_TYPE_VALIDATION_BIT_EXT |
-									 VK_DEBUG_UTILS_MESSAGE_TYPE_PERFORMANCE_BIT_EXT,
-			pfnUserCallback: cast(PFN_vkDebugUtilsMessengerCallbackEXT)&DebugCallback,
-		};
+				sType: VK_STRUCTURE_TYPE_DEBUG_UTILS_MESSENGER_CREATE_INFO_EXT,
+				messageSeverity: VK_DEBUG_UTILS_MESSAGE_SEVERITY_WARNING_BIT_EXT |
+												 VK_DEBUG_UTILS_MESSAGE_SEVERITY_ERROR_BIT_EXT,
+				messageType: VK_DEBUG_UTILS_MESSAGE_TYPE_GENERAL_BIT_EXT		|
+										 VK_DEBUG_UTILS_MESSAGE_TYPE_VALIDATION_BIT_EXT |
+										 VK_DEBUG_UTILS_MESSAGE_TYPE_PERFORMANCE_BIT_EXT,
+				pfnUserCallback: cast(PFN_vkDebugUtilsMessengerCallbackEXT)&DebugCallback,
+			};
+
+			if (g_DEBUG_PRINTF)
+			{
+				info.messageSeverity |= VK_DEBUG_UTILS_MESSAGE_SEVERITY_INFO_BIT_EXT;
+			}
 
 			VkResult result = vkCreateDebugUtilsMessengerEXT(vk.instance, &info, null, &vk.dbg_msg);
 			if (result != VK_SUCCESS)
diff --git a/src/gears/vulkan_logging.d b/src/gears/vulkan_logging.d
index ac02998..2accfc5 100644
--- a/src/gears/vulkan_logging.d
+++ b/src/gears/vulkan_logging.d
@@ -3,7 +3,7 @@ import std.stdio;
 import vulkan : Vulkan;
 import std.conv;
 import std.string;
-import core.stdc.string : strlen;
+import core.stdc.string : strlen, strcmp;
 
 extern(System) VkBool32
 DebugCallback(
@@ -15,6 +15,9 @@ DebugCallback(
 {
 	string ms, mt;
 
+	const(char)[] msg = callback_data.pMessage[0 .. strlen(callback_data.pMessage)];
+	bool debug_printf = strcmp(callback_data.pMessageIdName, "WARNING-DEBUG-PRINTF") == 0;
+
 	switch (message_severity) {
 	case VK_DEBUG_UTILS_MESSAGE_SEVERITY_VERBOSE_BIT_EXT:
 		ms = "VERBOSE";
@@ -60,9 +63,14 @@ DebugCallback(
 		break;
 	}
 
-	const char[] msg = callback_data.pMessage[0 .. strlen(callback_data.pMessage)];
-	
-	writefln("[%s: %s]\n%r\n", ms, mt, msg);
+	if (debug_printf)
+	{
+		writefln("SHADER PRINT: %s", msg);
+	}
+	else
+	{
+		writefln("[%s: %s]\n%r\n", ms, mt, msg);
+	}
 
 	return VK_FALSE;
 }
diff --git a/src/shaders/convert.comp.glsl b/src/shaders/convert.comp.glsl
index 0d5c687..d30f114 100644
--- a/src/shaders/convert.comp.glsl
+++ b/src/shaders/convert.comp.glsl
@@ -1,6 +1,7 @@
 #version 460
 
 #extension GL_EXT_shader_8bit_storage : require
+#extension GL_EXT_debug_printf : require
 
 layout (constant_id = 0) const int CHANNELS = 3;
 
@@ -31,23 +32,28 @@ void main()
 
 	if (CHANNELS == 1)
 	{
-		uint index = x + (y * PC.x);
+		uint index = x + y * PC.x;
 	
-		vec4 col = vec4(vec3(uint(src[index])), 1.0);
+		vec4 col = vec4(vec3(uint(src[index]) / 255.0), 1.0);
+		debugPrintfEXT("col = %v4f", col);
 		imageStore(dst, ivec2(x, y), col);
 	}
 	else if (CHANNELS == 2)
 	{
-		uint index = (x + (y * PC.x)) * 2;
+		uint index = (x + y * PC.x) * 2;
 
-		vec4 col = vec4(uint(src[index]), uint(src[index]), uint(src[index]), uint(src[index+1]));
+		float f = uint(src[index]) / 255.0;
+		float a = uint(src[index+1]) / 255.0;
+		vec4 col = vec4(f, f, f, a);
+		debugPrintfEXT("col = %v4f", col);
 		imageStore(dst, ivec2(x, y), col);
 	}
 	else if (CHANNELS == 3)
 	{
-		uint index = (x + (y * PC.x)) * 3;
+		uint index = (x + y * PC.x) * 3;
 
-		vec4 col = vec4(uint(src[index]), uint(src[index+1]), uint(src[index+2]), 1.0);
+		vec4 col = vec4(uint(src[index]) / 255.0, uint(src[index+1]) / 255.0, uint(src[index+2]) / 255.0, 1.0);
+		debugPrintfEXT("col = %v4f", col);
 		imageStore(dst, ivec2(x, y), col);
 	}
 }
diff --git a/src/shaders/structures.layout b/src/shaders/structures.layout
index 9262ee2..53f68cb 100644
--- a/src/shaders/structures.layout
+++ b/src/shaders/structures.layout
@@ -1,3 +1,7 @@
+// ****************************************************************************
+// **** STRUCTS MUST BE PACKED IN OPTIMAL PACKING ORDER TO MATCH D STRUCTS ****
+// ****************************************************************************
+
 layout (set = 0, binding = 0) uniform GlobalUniforms {
 	vec2 res;
 } G;
@@ -13,15 +17,15 @@ layout (set = 0, binding = 3) uniform sampler SamplerNearest;
 layout (set = 1, binding = 0) uniform texture2D Textures[];
 
 layout (set = 2, binding = 0) uniform Material {
+	vec4 ambient;
+	vec4 diffuse;
+	vec4 specular;
 	uint albedo_texture;
 	uint ambient_texture;
 	uint specular_texture;
 	bool albedo_has_texture;
 	bool ambient_has_texture;
 	bool specular_has_texture;
-	vec4 ambient;
-	vec4 diffuse;
-	vec4 specular;
 	float shininess;
 } Materials[];
 
diff --git a/src/shared/util.d b/src/shared/util.d
index a518157..a29e7b5 100644
--- a/src/shared/util.d
+++ b/src/shared/util.d
@@ -377,23 +377,17 @@ struct Vector(T, int S)
 		{
 			T r = 0.0;
 			T g = 0.0;
-			static if (S > 2)
-			T b = 0.0;
-			static if (S > 3)
-			T a = 0.0;
+			static if (S > 2) T b = 0.0;
+			static if (S > 3) T a = 0.0;
 		};
 		struct
 		{
 			T x;
 			T y;
-			static if (S > 2)
-			T z;
-			static if (S > 3)
-			T w;
+			static if (S > 2) T z;
+			static if (S > 3) T w;
 		};
-		static if (S == 4)
 		T[S] v;
-		float4 simd;
 	}
 }