New feature

Patch [#33445] - Experimental Cycles Hair Rendering (CPU only)

This patch allows hair data to be exported to cycles and introduces a new line segment primitive to render with.

The UI appears under the particle tab and there is a new hair info node available.

It is only available under the experimental feature set and for cpu rendering.

5 files changed, 159 insertions, 53 deletions

diff --git a/intern/cycles/kernel/svm/svm.h b/intern/cycles/kernel/svm/svm.h
index ec7978066c2..1f4857c0924 100644
--- a/intern/cycles/kernel/svm/svm.h
+++ b/intern/cycles/kernel/svm/svm.h
@@ -301,6 +301,12 @@ __device_noinline void svm_eval_nodes(KernelGlobals *kg, ShaderData *sd, ShaderT
 			case NODE_PARTICLE_INFO:
 				svm_node_particle_info(kg, sd, stack, node.y, node.z);
 				break;
+#ifdef __HAIR__
+			case NODE_HAIR_INFO:
+				svm_node_hair_info(kg, sd, stack, node.y, node.z);
+				break;
+#endif
+
 #endif
 			case NODE_CONVERT:
 				svm_node_convert(sd, stack, node.y, node.z, node.w);
diff --git a/intern/cycles/kernel/svm/svm_attribute.h b/intern/cycles/kernel/svm/svm_attribute.h
index ed70a6dc423..4f9dc4af007 100644
--- a/intern/cycles/kernel/svm/svm_attribute.h
+++ b/intern/cycles/kernel/svm/svm_attribute.h
@@ -58,27 +58,45 @@ __device void svm_node_attr(KernelGlobals *kg, ShaderData *sd, float *stack, uin
 
 	svm_node_attr_init(kg, sd, node, &type, &mesh_type, &elem, &offset, &out_offset);
 
-	/* fetch and store attribute */
-	if(type == NODE_ATTR_FLOAT) {
-		if(mesh_type == NODE_ATTR_FLOAT) {
-			float f = triangle_attribute_float(kg, sd, elem, offset, NULL, NULL);
-			stack_store_float(stack, out_offset, f);
-		}
+#ifdef __HAIR__
+	if (sd->curve_seg != ~0) {
+		/*currently strand attributes aren't enabled - only exports stored uvs*/
+		if(type == NODE_ATTR_FLOAT)
+			stack_store_float(stack, out_offset, 0.0f);
 		else {
-			float3 f = triangle_attribute_float3(kg, sd, elem, offset, NULL, NULL);
-			stack_store_float(stack, out_offset, average(f));
+			float4 sd2 = kernel_tex_fetch(__tri_woop, sd->prim*3+2);
+			float3 uv =  make_float3(sd2.z,sd2.w,0.0f);
+			stack_store_float3(stack, out_offset, uv);
 		}
 	}
-	else {
-		if(mesh_type == NODE_ATTR_FLOAT3) {
-			float3 f = triangle_attribute_float3(kg, sd, elem, offset, NULL, NULL);
-			stack_store_float3(stack, out_offset, f);
+	else
+	{
+#endif
+
+		/* fetch and store attribute */
+		if(type == NODE_ATTR_FLOAT) {
+			if(mesh_type == NODE_ATTR_FLOAT) {
+				float f = triangle_attribute_float(kg, sd, elem, offset, NULL, NULL);
+				stack_store_float(stack, out_offset, f);
+			}
+			else {
+				float3 f = triangle_attribute_float3(kg, sd, elem, offset, NULL, NULL);
+				stack_store_float(stack, out_offset, average(f));
+			}
 		}
 		else {
-			float f = triangle_attribute_float(kg, sd, elem, offset, NULL, NULL);
-			stack_store_float3(stack, out_offset, make_float3(f, f, f));
+			if(mesh_type == NODE_ATTR_FLOAT3) {
+				float3 f = triangle_attribute_float3(kg, sd, elem, offset, NULL, NULL);
+				stack_store_float3(stack, out_offset, f);
+			}
+			else {
+				float f = triangle_attribute_float(kg, sd, elem, offset, NULL, NULL);
+				stack_store_float3(stack, out_offset, make_float3(f, f, f));
+			}
 		}
+#ifdef __HAIR__
 	}
+#endif
 }
 
 __device void svm_node_attr_bump_dx(KernelGlobals *kg, ShaderData *sd, float *stack, uint4 node)
@@ -91,30 +109,43 @@ __device void svm_node_attr_bump_dx(KernelGlobals *kg, ShaderData *sd, float *st
 	svm_node_attr_init(kg, sd, node, &type, &mesh_type, &elem, &offset, &out_offset);
 
 	/* fetch and store attribute */
-	if(type == NODE_ATTR_FLOAT) {
-		if(mesh_type == NODE_ATTR_FLOAT) {
-			float dx;
-			float f = triangle_attribute_float(kg, sd, elem, offset, &dx, NULL);
-			stack_store_float(stack, out_offset, f+dx);
-		}
-		else {
-			float3 dx;
-			float3 f = triangle_attribute_float3(kg, sd, elem, offset, &dx, NULL);
-			stack_store_float(stack, out_offset, average(f+dx));
-		}
+#ifdef __HAIR__
+	if (sd->curve_seg != ~0) {
+		/*currently strand attributes aren't enabled*/
+		if(type == NODE_ATTR_FLOAT)
+			stack_store_float(stack, out_offset, 0.0f);
+		else
+			stack_store_float3(stack, out_offset,  make_float3(0.0f, 0.0f, 0.0f));
 	}
 	else {
-		if(mesh_type == NODE_ATTR_FLOAT3) {
-			float3 dx;
-			float3 f = triangle_attribute_float3(kg, sd, elem, offset, &dx, NULL);
-			stack_store_float3(stack, out_offset, f+dx);
+#endif
+		if(type == NODE_ATTR_FLOAT) {
+			if(mesh_type == NODE_ATTR_FLOAT) {
+				float dx;
+				float f = triangle_attribute_float(kg, sd, elem, offset, &dx, NULL);
+				stack_store_float(stack, out_offset, f+dx);
+			}
+			else {
+				float3 dx;
+				float3 f = triangle_attribute_float3(kg, sd, elem, offset, &dx, NULL);
+				stack_store_float(stack, out_offset, average(f+dx));
+			}
 		}
 		else {
-			float dx;
-			float f = triangle_attribute_float(kg, sd, elem, offset, &dx, NULL);
-			stack_store_float3(stack, out_offset, make_float3(f+dx, f+dx, f+dx));
+			if(mesh_type == NODE_ATTR_FLOAT3) {
+				float3 dx;
+				float3 f = triangle_attribute_float3(kg, sd, elem, offset, &dx, NULL);
+				stack_store_float3(stack, out_offset, f+dx);
+			}
+			else {
+				float dx;
+				float f = triangle_attribute_float(kg, sd, elem, offset, &dx, NULL);
+				stack_store_float3(stack, out_offset, make_float3(f+dx, f+dx, f+dx));
+			}
 		}
+#ifdef __HAIR__
 	}
+#endif
 }
 
 __device void svm_node_attr_bump_dy(KernelGlobals *kg, ShaderData *sd, float *stack, uint4 node)
@@ -127,30 +158,43 @@ __device void svm_node_attr_bump_dy(KernelGlobals *kg, ShaderData *sd, float *st
 	svm_node_attr_init(kg, sd, node, &type, &mesh_type, &elem, &offset, &out_offset);
 
 	/* fetch and store attribute */
-	if(type == NODE_ATTR_FLOAT) {
-		if(mesh_type == NODE_ATTR_FLOAT) {
-			float dy;
-			float f = triangle_attribute_float(kg, sd, elem, offset, NULL, &dy);
-			stack_store_float(stack, out_offset, f+dy);
-		}
-		else {
-			float3 dy;
-			float3 f = triangle_attribute_float3(kg, sd, elem, offset, NULL, &dy);
-			stack_store_float(stack, out_offset, average(f+dy));
-		}
+#ifdef __HAIR__
+	if (sd->curve_seg != ~0) {
+		/*currently strand attributes aren't enabled*/
+		if(type == NODE_ATTR_FLOAT)
+			stack_store_float(stack, out_offset, 0.0f);
+		else 
+			stack_store_float3(stack, out_offset,  make_float3(0.0f, 0.0f, 0.0f));
 	}
 	else {
-		if(mesh_type == NODE_ATTR_FLOAT3) {
-			float3 dy;
-			float3 f = triangle_attribute_float3(kg, sd, elem, offset, NULL, &dy);
-			stack_store_float3(stack, out_offset, f+dy);
+#endif
+		if(type == NODE_ATTR_FLOAT) {
+			if(mesh_type == NODE_ATTR_FLOAT) {
+				float dy;
+				float f = triangle_attribute_float(kg, sd, elem, offset, NULL, &dy);
+				stack_store_float(stack, out_offset, f+dy);
+			}
+			else {
+				float3 dy;
+				float3 f = triangle_attribute_float3(kg, sd, elem, offset, NULL, &dy);
+				stack_store_float(stack, out_offset, average(f+dy));
+			}
 		}
 		else {
-			float dy;
-			float f = triangle_attribute_float(kg, sd, elem, offset, NULL, &dy);
-			stack_store_float3(stack, out_offset, make_float3(f+dy, f+dy, f+dy));
+			if(mesh_type == NODE_ATTR_FLOAT3) {
+				float3 dy;
+				float3 f = triangle_attribute_float3(kg, sd, elem, offset, NULL, &dy);
+				stack_store_float3(stack, out_offset, f+dy);
+			}
+			else {
+				float dy;
+				float f = triangle_attribute_float(kg, sd, elem, offset, NULL, &dy);
+				stack_store_float3(stack, out_offset, make_float3(f+dy, f+dy, f+dy));
+			}
 		}
+#ifdef __HAIR__
 	}
+#endif
 }
 
 CCL_NAMESPACE_END
diff --git a/intern/cycles/kernel/svm/svm_geometry.h b/intern/cycles/kernel/svm/svm_geometry.h
index c4d03c1f948..e1b898e9b14 100644
--- a/intern/cycles/kernel/svm/svm_geometry.h
+++ b/intern/cycles/kernel/svm/svm_geometry.h
@@ -31,8 +31,11 @@ __device void svm_node_geometry(KernelGlobals *kg, ShaderData *sd, float *stack,
 		case NODE_GEOM_T: {
 			/* try to create spherical tangent from generated coordinates */
 			int attr_offset = (sd->object != ~0)? find_attribute(kg, sd, ATTR_STD_GENERATED): ATTR_STD_NOT_FOUND;
-
+#ifdef __HAIR__
+			if(attr_offset != ATTR_STD_NOT_FOUND && sd->curve_seg == ~0) {
+#else
 			if(attr_offset != ATTR_STD_NOT_FOUND) {
+#endif
 				data = triangle_attribute_float3(kg, sd, ATTR_ELEMENT_VERTEX, attr_offset, NULL, NULL);
 				data = make_float3(-(data.y - 0.5f), (data.x - 0.5f), 0.0f);
 				object_normal_transform(kg, sd, &data);
@@ -160,5 +163,38 @@ __device void svm_node_particle_info(KernelGlobals *kg, ShaderData *sd, float *s
 	}
 }
 
+#ifdef __HAIR__
+/* Hair Info */
+
+__device void svm_node_hair_info(KernelGlobals *kg, ShaderData *sd, float *stack, uint type, uint out_offset)
+{
+	float data;
+	float3 data3;
+
+	switch(type) {
+		case NODE_INFO_CURVE_IS_STRAND: {
+			data = !(sd->curve_seg == ~0);
+			stack_store_float(stack, out_offset, data);
+			break;
+		}
+		case NODE_INFO_CURVE_INTERCEPT: {
+			data = intercept(kg, sd->curve_seg, sd->prim, sd->u);
+			stack_store_float(stack, out_offset, data);
+			break;
+		}
+		case NODE_INFO_CURVE_THICKNESS: {
+			data = 2 * hair_radius(kg, sd->curve_seg, sd->u);
+			stack_store_float(stack, out_offset, data);
+			break;
+		}
+		case NODE_INFO_CURVE_TANGENT_NORMAL: {
+			data3 = hair_tangent_normal(kg, sd);
+			stack_store_float3(stack, out_offset, data3);
+			break;
+		}
+	}
+}
+#endif
+
 CCL_NAMESPACE_END
 
diff --git a/intern/cycles/kernel/svm/svm_tex_coord.h b/intern/cycles/kernel/svm/svm_tex_coord.h
index 9f2d3367420..5e7c92ba93c 100644
--- a/intern/cycles/kernel/svm/svm_tex_coord.h
+++ b/intern/cycles/kernel/svm/svm_tex_coord.h
@@ -242,7 +242,11 @@ __device void svm_node_normal_map(KernelGlobals *kg, ShaderData *sd, float *stac
 
 	if(space == NODE_NORMAL_MAP_TANGENT) {
 		/* tangent space */
-		if(sd->object == ~0) {
+#ifdef __HAIR__
+			if(sd->object == ~0 || sd->curve_seg != ~0) {
+#else
+			if(sd->object == ~0) {
+#endif
 			stack_store_float3(stack, normal_offset, make_float3(0.0f, 0.0f, 0.0f));
 			return;
 		}
@@ -297,7 +301,11 @@ __device void svm_node_tangent(KernelGlobals *kg, ShaderData *sd, float *stack,
 		/* UV map */
 		int attr_offset = find_attribute(kg, sd, node.z);
 
+#ifdef __HAIR__
+		if(attr_offset == ATTR_STD_NOT_FOUND || sd->curve_seg != ~0)
+#else
 		if(attr_offset == ATTR_STD_NOT_FOUND)
+#endif
 			tangent = make_float3(0.0f, 0.0f, 0.0f);
 		else
 			tangent = triangle_attribute_float3(kg, sd, ATTR_ELEMENT_CORNER, attr_offset, NULL, NULL);
@@ -307,7 +315,11 @@ __device void svm_node_tangent(KernelGlobals *kg, ShaderData *sd, float *stack,
 		int attr_offset = find_attribute(kg, sd, node.z);
 		float3 generated;
 
+#ifdef __HAIR__
+		if(attr_offset == ATTR_STD_NOT_FOUND || sd->curve_seg != ~0)
+#else
 		if(attr_offset == ATTR_STD_NOT_FOUND)
+#endif
 			generated = sd->P;
 		else
 			generated = triangle_attribute_float3(kg, sd, ATTR_ELEMENT_VERTEX, attr_offset, NULL, NULL);
diff --git a/intern/cycles/kernel/svm/svm_types.h b/intern/cycles/kernel/svm/svm_types.h
index e1a583625fc..57177eec48f 100644
--- a/intern/cycles/kernel/svm/svm_types.h
+++ b/intern/cycles/kernel/svm/svm_types.h
@@ -97,7 +97,8 @@ typedef enum NodeType {
 	NODE_CLOSURE_SET_NORMAL,
 	NODE_CLOSURE_AMBIENT_OCCLUSION,
 	NODE_TANGENT,
-	NODE_NORMAL_MAP
+	NODE_NORMAL_MAP,
+	NODE_HAIR_INFO
 } NodeType;
 
 typedef enum NodeAttributeType {
@@ -132,6 +133,13 @@ typedef enum NodeParticleInfo {
 	NODE_INFO_PAR_ANGULAR_VELOCITY
 } NodeParticleInfo;
 
+typedef enum NodeHairInfo {
+	NODE_INFO_CURVE_IS_STRAND,
+	NODE_INFO_CURVE_INTERCEPT,
+	NODE_INFO_CURVE_THICKNESS,
+	NODE_INFO_CURVE_TANGENT_NORMAL
+} NodeHairInfo;
+
 typedef enum NodeLightPath {
 	NODE_LP_camera = 0,
 	NODE_LP_shadow,