blender/intern/cycles/kernel/kernel_triangle.h
Brecht Van Lommel 57cf48e7c6 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

195 lines
7.2 KiB
C

/*
* 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
/* Point on triangle for Moller-Trumbore triangles */
__device_inline float3 triangle_point_MT(KernelGlobals *kg, int tri_index, float u, float v)
{
/* load triangle vertices */
float3 tri_vindex = float4_to_float3(kernel_tex_fetch(__tri_vindex, tri_index));
float3 v0 = float4_to_float3(kernel_tex_fetch(__tri_verts, __float_as_int(tri_vindex.x)));
float3 v1 = float4_to_float3(kernel_tex_fetch(__tri_verts, __float_as_int(tri_vindex.y)));
float3 v2 = float4_to_float3(kernel_tex_fetch(__tri_verts, __float_as_int(tri_vindex.z)));
/* compute point */
float t = 1.0f - u - v;
return (u*v0 + v*v1 + t*v2);
}
/* Sample point on triangle */
__device_inline float3 triangle_sample_MT(KernelGlobals *kg, int tri_index, float randu, float randv)
{
/* compute point */
randu = sqrtf(randu);
float u = 1.0f - randu;
float v = randv*randu;
return triangle_point_MT(kg, tri_index, u, v);
}
/* Normal for Moller-Trumbore triangles */
__device_inline float3 triangle_normal_MT(KernelGlobals *kg, int tri_index, int *shader)
{
#if 0
/* load triangle vertices */
float3 tri_vindex = float4_to_float3(kernel_tex_fetch(__tri_vindex, tri_index));
float3 v0 = float4_to_float3(kernel_tex_fetch(__tri_verts, __float_as_int(tri_vindex.x)));
float3 v1 = float4_to_float3(kernel_tex_fetch(__tri_verts, __float_as_int(tri_vindex.y)));
float3 v2 = float4_to_float3(kernel_tex_fetch(__tri_verts, __float_as_int(tri_vindex.z)));
/* compute normal */
return normalize(cross(v2 - v0, v1 - v0));
#else
float4 Nm = kernel_tex_fetch(__tri_normal, tri_index);
*shader = __float_as_int(Nm.w);
return make_float3(Nm.x, Nm.y, Nm.z);
#endif
}
/* Return 3 triangle vertex locations */
__device_inline void triangle_vertices(KernelGlobals *kg, int tri_index, float3 P[3])
{
/* load triangle vertices */
float3 tri_vindex = float4_to_float3(kernel_tex_fetch(__tri_vindex, tri_index));
P[0] = float4_to_float3(kernel_tex_fetch(__tri_verts, __float_as_int(tri_vindex.x)));
P[1] = float4_to_float3(kernel_tex_fetch(__tri_verts, __float_as_int(tri_vindex.y)));
P[2] = float4_to_float3(kernel_tex_fetch(__tri_verts, __float_as_int(tri_vindex.z)));
}
__device_inline float3 triangle_smooth_normal(KernelGlobals *kg, int tri_index, float u, float v)
{
/* load triangle vertices */
float3 tri_vindex = float4_to_float3(kernel_tex_fetch(__tri_vindex, tri_index));
float3 n0 = float4_to_float3(kernel_tex_fetch(__tri_vnormal, __float_as_int(tri_vindex.x)));
float3 n1 = float4_to_float3(kernel_tex_fetch(__tri_vnormal, __float_as_int(tri_vindex.y)));
float3 n2 = float4_to_float3(kernel_tex_fetch(__tri_vnormal, __float_as_int(tri_vindex.z)));
return normalize((1.0f - u - v)*n2 + u*n0 + v*n1);
}
__device_inline void triangle_dPdudv(KernelGlobals *kg, float3 *dPdu, float3 *dPdv, int tri)
{
/* fetch triangle vertex coordinates */
float3 tri_vindex = float4_to_float3(kernel_tex_fetch(__tri_vindex, tri));
float3 p0 = float4_to_float3(kernel_tex_fetch(__tri_verts, __float_as_int(tri_vindex.x)));
float3 p1 = float4_to_float3(kernel_tex_fetch(__tri_verts, __float_as_int(tri_vindex.y)));
float3 p2 = float4_to_float3(kernel_tex_fetch(__tri_verts, __float_as_int(tri_vindex.z)));
/* compute derivatives of P w.r.t. uv */
*dPdu = (p0 - p2);
*dPdv = (p1 - p2);
}
/* attributes */
__device float triangle_attribute_float(KernelGlobals *kg, const ShaderData *sd, AttributeElement elem, int offset, float *dx, float *dy)
{
if(elem == ATTR_ELEMENT_FACE) {
if(dx) *dx = 0.0f;
if(dy) *dy = 0.0f;
return kernel_tex_fetch(__attributes_float, offset + sd->prim);
}
else if(elem == ATTR_ELEMENT_VERTEX) {
float3 tri_vindex = float4_to_float3(kernel_tex_fetch(__tri_vindex, sd->prim));
float f0 = kernel_tex_fetch(__attributes_float, offset + __float_as_int(tri_vindex.x));
float f1 = kernel_tex_fetch(__attributes_float, offset + __float_as_int(tri_vindex.y));
float f2 = kernel_tex_fetch(__attributes_float, offset + __float_as_int(tri_vindex.z));
#ifdef __RAY_DIFFERENTIALS__
if(dx) *dx = sd->du.dx*f0 + sd->dv.dx*f1 - (sd->du.dx + sd->dv.dx)*f2;
if(dy) *dy = sd->du.dy*f0 + sd->dv.dy*f1 - (sd->du.dy + sd->dv.dy)*f2;
#endif
return sd->u*f0 + sd->v*f1 + (1.0f - sd->u - sd->v)*f2;
}
else if(elem == ATTR_ELEMENT_CORNER) {
int tri = offset + sd->prim*3;
float f0 = kernel_tex_fetch(__attributes_float, tri + 0);
float f1 = kernel_tex_fetch(__attributes_float, tri + 1);
float f2 = kernel_tex_fetch(__attributes_float, tri + 2);
#ifdef __RAY_DIFFERENTIALS__
if(dx) *dx = sd->du.dx*f0 + sd->dv.dx*f1 - (sd->du.dx + sd->dv.dx)*f2;
if(dy) *dy = sd->du.dy*f0 + sd->dv.dy*f1 - (sd->du.dy + sd->dv.dy)*f2;
#endif
return sd->u*f0 + sd->v*f1 + (1.0f - sd->u - sd->v)*f2;
}
else {
if(dx) *dx = 0.0f;
if(dy) *dy = 0.0f;
return 0.0f;
}
}
__device float3 triangle_attribute_float3(KernelGlobals *kg, const ShaderData *sd, AttributeElement elem, int offset, float3 *dx, float3 *dy)
{
if(elem == ATTR_ELEMENT_FACE) {
if(dx) *dx = make_float3(0.0f, 0.0f, 0.0f);
if(dy) *dy = make_float3(0.0f, 0.0f, 0.0f);
return float4_to_float3(kernel_tex_fetch(__attributes_float3, offset + sd->prim));
}
else if(elem == ATTR_ELEMENT_VERTEX) {
float3 tri_vindex = float4_to_float3(kernel_tex_fetch(__tri_vindex, sd->prim));
float3 f0 = float4_to_float3(kernel_tex_fetch(__attributes_float3, offset + __float_as_int(tri_vindex.x)));
float3 f1 = float4_to_float3(kernel_tex_fetch(__attributes_float3, offset + __float_as_int(tri_vindex.y)));
float3 f2 = float4_to_float3(kernel_tex_fetch(__attributes_float3, offset + __float_as_int(tri_vindex.z)));
#ifdef __RAY_DIFFERENTIALS__
if(dx) *dx = sd->du.dx*f0 + sd->dv.dx*f1 - (sd->du.dx + sd->dv.dx)*f2;
if(dy) *dy = sd->du.dy*f0 + sd->dv.dy*f1 - (sd->du.dy + sd->dv.dy)*f2;
#endif
return sd->u*f0 + sd->v*f1 + (1.0f - sd->u - sd->v)*f2;
}
else if(elem == ATTR_ELEMENT_CORNER) {
int tri = offset + sd->prim*3;
float3 f0 = float4_to_float3(kernel_tex_fetch(__attributes_float3, tri + 0));
float3 f1 = float4_to_float3(kernel_tex_fetch(__attributes_float3, tri + 1));
float3 f2 = float4_to_float3(kernel_tex_fetch(__attributes_float3, tri + 2));
#ifdef __RAY_DIFFERENTIALS__
if(dx) *dx = sd->du.dx*f0 + sd->dv.dx*f1 - (sd->du.dx + sd->dv.dx)*f2;
if(dy) *dy = sd->du.dy*f0 + sd->dv.dy*f1 - (sd->du.dy + sd->dv.dy)*f2;
#endif
return sd->u*f0 + sd->v*f1 + (1.0f - sd->u - sd->v)*f2;
}
else {
if(dx) *dx = make_float3(0.0f, 0.0f, 0.0f);
if(dy) *dy = make_float3(0.0f, 0.0f, 0.0f);
return make_float3(0.0f, 0.0f, 0.0f);
}
}
CCL_NAMESPACE_END