Cycles Hair: refactoring to support generic attributes for hair curves. There

should be no functional changes yet. UV, tangent and intercept are now stored as attributes, with the intention to add more like multiple uv's, vertex colors, generated coordinates and motion vectors later. Things got a bit messy due to having both triangle and curve data in the same mesh data structure, which also gives us two sets of attributes. This will get cleaned up when we split the mesh class.
2013-01-03 12:08:54 +00:00
parent 8ca977b16e
commit 57cf48e7c6
41 changed files with 1052 additions and 945 deletions
--- a/intern/cycles/kernel/kernel_curve.h
+++ b/intern/cycles/kernel/kernel_curve.h
@@ -0,0 +1,140 @@
+/*
+ * Copyright 2011, Blender Foundation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+CCL_NAMESPACE_BEGIN
+
+#ifdef __HAIR__
+
+/* curve attributes */
+
+__device float curve_attribute_float(KernelGlobals *kg, const ShaderData *sd, AttributeElement elem, int offset, float *dx, float *dy)
+{
+	if(elem == ATTR_ELEMENT_CURVE_SEGMENT) {
+#ifdef __RAY_DIFFERENTIALS__
+		if(dx) *dx = 0.0f;
+		if(dy) *dy = 0.0f;
+#endif
+
+		return kernel_tex_fetch(__attributes_float, offset + sd->curve_seg);
+	}
+	else if(elem == ATTR_ELEMENT_CURVE_KEY) {
+		float4 segment = kernel_tex_fetch(__curve_segments, sd->curve_seg);
+
+		float f0 = kernel_tex_fetch(__attributes_float, offset + __float_as_int(segment.x));
+		float f1 = kernel_tex_fetch(__attributes_float, offset + __float_as_int(segment.y));
+
+#ifdef __RAY_DIFFERENTIALS__
+		if(dx) *dx = sd->du.dx*(f1 - f0);
+		if(dy) *dy = 0.0f;
+#endif
+
+		return (1.0f - sd->u)*f0 + sd->u*f1;
+	}
+	else {
+#ifdef __RAY_DIFFERENTIALS__
+		if(dx) *dx = 0.0f;
+		if(dy) *dy = 0.0f;
+#endif
+
+		return 0.0f;
+	}
+}
+
+__device float3 curve_attribute_float3(KernelGlobals *kg, const ShaderData *sd, AttributeElement elem, int offset, float3 *dx, float3 *dy)
+{
+	if(elem == ATTR_ELEMENT_CURVE_SEGMENT) {
+		/* idea: we can't derive any useful differentials here, but for tiled
+		 * mipmap image caching it would be useful to avoid reading the highest
+		 * detail level always. maybe a derivative based on the hair density
+		 * could be computed somehow? */
+#ifdef __RAY_DIFFERENTIALS__
+		if(dx) *dx = make_float3(0.0f, 0.0f, 0.0f);
+		if(dy) *dy = make_float3(0.0f, 0.0f, 0.0f);
+#endif
+
+		return float4_to_float3(kernel_tex_fetch(__attributes_float3, offset + sd->curve_seg));
+	}
+	else if(elem == ATTR_ELEMENT_CURVE_KEY) {
+		float4 segment = kernel_tex_fetch(__curve_segments, sd->curve_seg);
+
+		float3 f0 = float4_to_float3(kernel_tex_fetch(__attributes_float3, offset + __float_as_int(segment.x)));
+		float3 f1 = float4_to_float3(kernel_tex_fetch(__attributes_float3, offset + __float_as_int(segment.y)));
+
+#ifdef __RAY_DIFFERENTIALS__
+		if(dx) *dx = sd->du.dx*(f1 - f0);
+		if(dy) *dy = make_float3(0.0f, 0.0f, 0.0f);
+#endif
+
+		return (1.0f - sd->u)*f0 + sd->u*f1;
+	}
+	else {
+#ifdef __RAY_DIFFERENTIALS__
+		if(dx) *dx = make_float3(0.0f, 0.0f, 0.0f);
+		if(dy) *dy = make_float3(0.0f, 0.0f, 0.0f);
+#endif
+
+		return make_float3(0.0f, 0.0f, 0.0f);
+	}
+}
+
+/* hair info node functions */
+
+__device float curve_thickness(KernelGlobals *kg, ShaderData *sd)
+{
+	int prim = sd->curve_seg;
+	float u = sd->u;
+	float r = 0.0f;
+
+	if(prim != -1) {
+		float4 v00 = kernel_tex_fetch(__curve_segments, prim);
+
+		int v1 = __float_as_int(v00.x);
+		int v2 = __float_as_int(v00.y);
+
+		float4 P1 = kernel_tex_fetch(__curve_keys, v1);
+		float4 P2 = kernel_tex_fetch(__curve_keys, v2);
+		r = (P2.w - P1.w) * u + P1.w;
+	}
+
+	return r*2.0f;
+}
+
+__device float3 curve_tangent_normal(KernelGlobals *kg, ShaderData *sd)
+{	
+	float3 tgN = make_float3(0.0f,0.0f,0.0f);
+
+	if(sd->curve_seg != ~0) {
+		float normalmix = kernel_data.curve_kernel_data.normalmix;
+
+		tgN = -(-sd->I - sd->dPdu * (dot(sd->dPdu,-sd->I) * normalmix / len_squared(sd->dPdu)));
+		tgN = normalize(tgN);
+
+		/* need to find suitable scaled gd for corrected normal */
+#if 0
+		if (kernel_data.curve_kernel_data.use_tangent_normal_correction)
+			tgN = normalize(tgN - gd * sd->dPdu);
+#endif
+	}
+
+	return tgN;
+}
+
+#endif
+
+CCL_NAMESPACE_END
+