diff --git a/Sources/backends/hlsl.c b/Sources/backends/hlsl.c
index 838d23d..e2851c3 100644
--- a/Sources/backends/hlsl.c
+++ b/Sources/backends/hlsl.c
@@ -607,6 +607,14 @@ static void write_functions(char *hlsl, size_t *offset, shader_stage stage, func
 					check(o->op_call.parameters_size == 0, context, "group_index can not have a parameter");
 					*offset += sprintf(&hlsl[*offset], "%s _%" PRIu64 " = WorldRayDirection();\n", type_string(o->op_call.var.type.type), o->op_call.var.index);
 				}
+				else if (o->op_call.func == add_name("ray_index")) {
+					check(o->op_call.parameters_size == 0, context, "group_index can not have a parameter");
+					*offset += sprintf(&hlsl[*offset], "%s _%" PRIu64 " = DispatchRaysIndex();\n", type_string(o->op_call.var.type.type), o->op_call.var.index);
+				}
+				else if (o->op_call.func == add_name("ray_dimensions")) {
+					check(o->op_call.parameters_size == 0, context, "group_index can not have a parameter");
+					*offset += sprintf(&hlsl[*offset], "%s _%" PRIu64 " = DispatchRaysDimensions();\n", type_string(o->op_call.var.type.type), o->op_call.var.index);
+				}
 				else {
 					*offset += sprintf(&hlsl[*offset], "%s _%" PRIu64 " = %s(", type_string(o->op_call.var.type.type), o->op_call.var.index,
 					                   function_string(o->op_call.func));
diff --git a/Sources/functions.c b/Sources/functions.c
index 1e70a9c..bc8304e 100644
--- a/Sources/functions.c
+++ b/Sources/functions.c
@@ -49,6 +49,15 @@ static void add_func_float3(char *name) {
 	f->block = NULL;
 }
 
+static void add_func_uint3(char *name) {
+	function_id func = add_function(add_name(name));
+	function *f = get_function(func);
+	init_type_ref(&f->return_type, add_name("uint3"));
+	f->return_type.type = find_type_by_ref(&f->return_type);
+	f->parameters_size = 0;
+	f->block = NULL;
+}
+
 static void add_func_float_float(char *name) {
 	function_id func = add_function(add_name(name));
 	function *f = get_function(func);
@@ -149,6 +158,8 @@ void functions_init(void) {
 	add_func_float3("world_ray_direction");
 	add_func_float3_float3("normalize");
 	add_func_float_float("saturate");
+	add_func_uint3("ray_index");
+	add_func_float3("ray_dimensions");
 }
 
 static void grow_if_needed(uint64_t size) {
diff --git a/Sources/kong.c b/Sources/kong.c
index 142f14a..54381cc 100644
--- a/Sources/kong.c
+++ b/Sources/kong.c
@@ -108,7 +108,7 @@ void resolve_member_type(statement *parent_block, type_ref parent_type, expressi
 	e->type = e->member.right->type;
 }
 
-static bool types_compatible(type_id left, type_id right){
+static bool types_compatible(type_id left, type_id right) {
 	if (left == right) {
 		return true;
 	}
@@ -126,6 +126,32 @@ static bool types_compatible(type_id left, type_id right){
 		return true;
 	}
 
+	if ((left == uint_id && right == float_id) || (left == float_id && right == uint_id)) {
+		return true;
+	}
+	if ((left == uint2_id && right == float2_id) || (left == float2_id && right == uint2_id)) {
+		return true;
+	}
+	if ((left == uint3_id && right == float3_id) || (left == float3_id && right == uint3_id)) {
+		return true;
+	}
+	if ((left == uint4_id && right == float4_id) || (left == float4_id && right == uint4_id)) {
+		return true;
+	}
+
+	if ((left == uint_id && right == int_id) || (left == int_id && right == uint_id)) {
+		return true;
+	}
+	if ((left == uint2_id && right == int2_id) || (left == int2_id && right == uint2_id)) {
+		return true;
+	}
+	if ((left == uint3_id && right == int3_id) || (left == int3_id && right == uint3_id)) {
+		return true;
+	}
+	if ((left == uint4_id && right == int4_id) || (left == int4_id && right == uint4_id)) {
+		return true;
+	}
+
 	return false;
 }
 
@@ -162,6 +188,56 @@ static type_ref upgrade_type(type_ref left_type, type_ref right_type) {
 		return left_type;
 	}
 
+	if (left == uint_id && right == float_id) {
+		return right_type;
+	}
+	if (left == float_id && right == uint_id) {
+		return left_type;
+	}
+	if (left == uint2_id && right == float2_id) {
+		return right_type;
+	}
+	if (left == float2_id && right == uint2_id) {
+		return left_type;
+	}
+	if (left == uint3_id && right == float3_id) {
+		return right_type;
+	}
+	if (left == float3_id && right == uint3_id) {
+		return left_type;
+	}
+	if (left == uint4_id && right == float4_id) {
+		return right_type;
+	}
+	if (left == float4_id && right == uint4_id) {
+		return left_type;
+	}
+
+	if (left == uint_id && right == int_id) {
+		return right_type;
+	}
+	if (left == int_id && right == uint_id) {
+		return left_type;
+	}
+	if (left == uint2_id && right == int2_id) {
+		return right_type;
+	}
+	if (left == int2_id && right == uint2_id) {
+		return left_type;
+	}
+	if (left == uint3_id && right == int3_id) {
+		return right_type;
+	}
+	if (left == int3_id && right == uint3_id) {
+		return left_type;
+	}
+	if (left == uint4_id && right == int4_id) {
+		return right_type;
+	}
+	if (left == int4_id && right == uint4_id) {
+		return left_type;
+	}
+
 	kong_log(LOG_LEVEL_WARNING, "Suspicious type upgrade");
 	return left_type;
 }
diff --git a/Sources/types.c b/Sources/types.c
index 2f46964..d69bd2c 100644
--- a/Sources/types.c
+++ b/Sources/types.c
@@ -20,6 +20,10 @@ type_id int_id;
 type_id int2_id;
 type_id int3_id;
 type_id int4_id;
+type_id uint_id;
+type_id uint2_id;
+type_id uint3_id;
+type_id uint4_id;
 type_id bool_id;
 type_id function_type_id;
 type_id tex2d_type_id;
@@ -232,6 +236,96 @@ static void int4_found_int4(char *permutation) {
 	++t->members.size;
 }
 
+static void uint2_found_uint(char *permutation) {
+	type *t = get_type(uint2_id);
+	debug_context context = {0};
+	check(t->members.size < MAX_MEMBERS, context, "Out of members");
+	t->members.m[t->members.size].name = add_name(permutation);
+	t->members.m[t->members.size].type.type = uint_id;
+	t->members.m[t->members.size].type.array_size = 0;
+	++t->members.size;
+}
+
+static void uint2_found_uint2(char *permutation) {
+	type *t = get_type(uint2_id);
+	debug_context context = {0};
+	check(t->members.size < MAX_MEMBERS, context, "Out of members");
+	t->members.m[t->members.size].name = add_name(permutation);
+	t->members.m[t->members.size].type.type = uint2_id;
+	t->members.m[t->members.size].type.array_size = 0;
+	++t->members.size;
+}
+
+static void uint3_found_uint(char *permutation) {
+	type *t = get_type(uint3_id);
+	debug_context context = {0};
+	check(t->members.size < MAX_MEMBERS, context, "Out of members");
+	t->members.m[t->members.size].name = add_name(permutation);
+	t->members.m[t->members.size].type.type = uint_id;
+	t->members.m[t->members.size].type.array_size = 0;
+	++t->members.size;
+}
+
+static void uint3_found_uint2(char *permutation) {
+	type *t = get_type(uint3_id);
+	debug_context context = {0};
+	check(t->members.size < MAX_MEMBERS, context, "Out of members");
+	t->members.m[t->members.size].name = add_name(permutation);
+	t->members.m[t->members.size].type.type = uint2_id;
+	t->members.m[t->members.size].type.array_size = 0;
+	++t->members.size;
+}
+
+static void uint3_found_uint3(char *permutation) {
+	type *t = get_type(uint3_id);
+	debug_context context = {0};
+	check(t->members.size < MAX_MEMBERS, context, "Out of members");
+	t->members.m[t->members.size].name = add_name(permutation);
+	t->members.m[t->members.size].type.type = uint3_id;
+	t->members.m[t->members.size].type.array_size = 0;
+	++t->members.size;
+}
+
+static void uint4_found_uint(char *permutation) {
+	type *t = get_type(uint4_id);
+	debug_context context = {0};
+	check(t->members.size < MAX_MEMBERS, context, "Out of members");
+	t->members.m[t->members.size].name = add_name(permutation);
+	t->members.m[t->members.size].type.type = uint_id;
+	t->members.m[t->members.size].type.array_size = 0;
+	++t->members.size;
+}
+
+static void uint4_found_uint2(char *permutation) {
+	type *t = get_type(uint4_id);
+	debug_context context = {0};
+	check(t->members.size < MAX_MEMBERS, context, "Out of members");
+	t->members.m[t->members.size].name = add_name(permutation);
+	t->members.m[t->members.size].type.type = uint2_id;
+	t->members.m[t->members.size].type.array_size = 0;
+	++t->members.size;
+}
+
+static void uint4_found_uint3(char *permutation) {
+	type *t = get_type(uint4_id);
+	debug_context context = {0};
+	check(t->members.size < MAX_MEMBERS, context, "Out of members");
+	t->members.m[t->members.size].name = add_name(permutation);
+	t->members.m[t->members.size].type.type = uint3_id;
+	t->members.m[t->members.size].type.array_size = 0;
+	++t->members.size;
+}
+
+static void uint4_found_uint4(char *permutation) {
+	type *t = get_type(uint4_id);
+	debug_context context = {0};
+	check(t->members.size < MAX_MEMBERS, context, "Out of members");
+	t->members.m[t->members.size].name = add_name(permutation);
+	t->members.m[t->members.size].type.type = uint4_id;
+	t->members.m[t->members.size].type.array_size = 0;
+	++t->members.size;
+}
+
 void init_type_ref(type_ref *t, name_id name) {
 	t->name = name;
 	t->type = NO_TYPE;
@@ -261,6 +355,8 @@ void types_init(void) {
 	get_type(float_id)->built_in = true;
 	int_id = add_type(add_name("int"));
 	get_type(int_id)->built_in = true;
+	uint_id = add_type(add_name("uint"));
+	get_type(uint_id)->built_in = true;
 
 	{
 		float2_id = add_type(add_name("float2"));
@@ -340,6 +436,45 @@ void types_init(void) {
 		permute(letters, (int)strlen(letters), 3, int4_found_int4);
 	}
 
+	{
+		uint2_id = add_type(add_name("uint2"));
+		get_type(uint2_id)->built_in = true;
+		const char *letters = "xy";
+		permute(letters, (int)strlen(letters), 1, uint2_found_uint);
+		permute(letters, (int)strlen(letters), 2, uint2_found_uint2);
+		letters = "rg";
+		permute(letters, (int)strlen(letters), 1, uint2_found_uint);
+		permute(letters, (int)strlen(letters), 2, uint2_found_uint2);
+	}
+
+	{
+		uint3_id = add_type(add_name("uint3"));
+		get_type(uint3_id)->built_in = true;
+		const char *letters = "xyz";
+		permute(letters, (int)strlen(letters), 1, uint3_found_uint);
+		permute(letters, (int)strlen(letters), 2, uint3_found_uint2);
+		permute(letters, (int)strlen(letters), 3, uint3_found_uint3);
+		letters = "rgb";
+		permute(letters, (int)strlen(letters), 1, uint3_found_uint);
+		permute(letters, (int)strlen(letters), 2, uint3_found_uint2);
+		permute(letters, (int)strlen(letters), 3, uint3_found_uint3);
+	}
+
+	{
+		uint4_id = add_type(add_name("uint4"));
+		get_type(uint4_id)->built_in = true;
+		const char *letters = "xyzw";
+		permute(letters, (int)strlen(letters), 1, uint4_found_uint);
+		permute(letters, (int)strlen(letters), 2, uint4_found_uint2);
+		permute(letters, (int)strlen(letters), 3, uint4_found_uint3);
+		permute(letters, (int)strlen(letters), 3, uint4_found_uint4);
+		letters = "rgba";
+		permute(letters, (int)strlen(letters), 1, uint4_found_uint);
+		permute(letters, (int)strlen(letters), 2, uint4_found_uint2);
+		permute(letters, (int)strlen(letters), 3, uint4_found_uint3);
+		permute(letters, (int)strlen(letters), 3, uint4_found_uint4);
+	}
+
 	{
 		float4x4_id = add_type(add_name("float4x4"));
 		get_type(float4x4_id)->built_in = true;
diff --git a/Sources/types.h b/Sources/types.h
index b65a20d..c072fb7 100644
--- a/Sources/types.h
+++ b/Sources/types.h
@@ -87,6 +87,10 @@ extern type_id int_id;
 extern type_id int2_id;
 extern type_id int3_id;
 extern type_id int4_id;
+extern type_id uint_id;
+extern type_id uint2_id;
+extern type_id uint3_id;
+extern type_id uint4_id;
 extern type_id bool_id;
 extern type_id tex2d_type_id;
 extern type_id texcube_type_id;
diff --git a/tests/in/test.kong b/tests/in/test.kong
index ec36b72..9f9d7db 100644
--- a/tests/in/test.kong
+++ b/tests/in/test.kong
@@ -55,7 +55,13 @@ struct Payload {
 }
 
 fun sendrays(): void {
+    var idx: uint2 = ray_index().xy;
+    var size: float2 = ray_dimensions().xy;
 
+    var uv: float2 = idx / size;
+    var target: float3 = float3((uv.x * 2 - 1) * 1.8 * (size.x / size.y),
+                           (1 - uv.y) * 4 - 2 + camera.y,
+                           0);
 }
 
 fun raymissed(payload: Payload): void {