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blender-archive/intern/cycles/kernel/geom/motion_triangle_intersect.h
Brecht Van Lommel fd25e883e2 Cycles: remove prefix from source code file names
Remove prefix of filenames that is the same as the folder name. This used
to help when #includes were using individual files, but now they are always
relative to the cycles root directory and so the prefixes are redundant.

For patches and branches, git merge and rebase should be able to detect the
renames and move over code to the right file.
2021-10-26 15:37:04 +02:00

304 lines
9.8 KiB
C++

/*
* Copyright 2011-2016 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* Motion Triangle Primitive
*
* These are stored as regular triangles, plus extra positions and normals at
* times other than the frame center. Computing the triangle vertex positions
* or normals at a given ray time is a matter of interpolation of the two steps
* between which the ray time lies.
*
* The extra positions and normals are stored as ATTR_STD_MOTION_VERTEX_POSITION
* and ATTR_STD_MOTION_VERTEX_NORMAL mesh attributes.
*/
#pragma once
CCL_NAMESPACE_BEGIN
/* Refine triangle intersection to more precise hit point. For rays that travel
* far the precision is often not so good, this reintersects the primitive from
* a closer distance.
*/
ccl_device_inline float3 motion_triangle_refine(KernelGlobals kg,
ccl_private ShaderData *sd,
float3 P,
float3 D,
float t,
const int isect_object,
const int isect_prim,
float3 verts[3])
{
#ifdef __INTERSECTION_REFINE__
if (!(sd->object_flag & SD_OBJECT_TRANSFORM_APPLIED)) {
if (UNLIKELY(t == 0.0f)) {
return P;
}
const Transform tfm = object_get_inverse_transform(kg, sd);
P = transform_point(&tfm, P);
D = transform_direction(&tfm, D * t);
D = normalize_len(D, &t);
}
P = P + D * t;
/* Compute refined intersection distance. */
const float3 e1 = verts[0] - verts[2];
const float3 e2 = verts[1] - verts[2];
const float3 s1 = cross(D, e2);
const float invdivisor = 1.0f / dot(s1, e1);
const float3 d = P - verts[2];
const float3 s2 = cross(d, e1);
float rt = dot(e2, s2) * invdivisor;
/* Compute refined position. */
P = P + D * rt;
if (!(sd->object_flag & SD_OBJECT_TRANSFORM_APPLIED)) {
const Transform tfm = object_get_transform(kg, sd);
P = transform_point(&tfm, P);
}
return P;
#else
return P + D * t;
#endif
}
/* Same as above, except that t is assumed to be in object space
* for instancing.
*/
#ifdef __BVH_LOCAL__
# if defined(__KERNEL_CUDA__) && (defined(i386) || defined(_M_IX86))
ccl_device_noinline
# else
ccl_device_inline
# endif
float3
motion_triangle_refine_local(KernelGlobals kg,
ccl_private ShaderData *sd,
float3 P,
float3 D,
float t,
const int isect_object,
const int isect_prim,
float3 verts[3])
{
# ifdef __KERNEL_OPTIX__
/* t is always in world space with OptiX. */
return motion_triangle_refine(kg, sd, P, D, t, isect_object, isect_prim, verts);
# else
# ifdef __INTERSECTION_REFINE__
if (!(sd->object_flag & SD_OBJECT_TRANSFORM_APPLIED)) {
const Transform tfm = object_get_inverse_transform(kg, sd);
P = transform_point(&tfm, P);
D = transform_direction(&tfm, D);
D = normalize(D);
}
P = P + D * t;
/* compute refined intersection distance */
const float3 e1 = verts[0] - verts[2];
const float3 e2 = verts[1] - verts[2];
const float3 s1 = cross(D, e2);
const float invdivisor = 1.0f / dot(s1, e1);
const float3 d = P - verts[2];
const float3 s2 = cross(d, e1);
float rt = dot(e2, s2) * invdivisor;
P = P + D * rt;
if (!(sd->object_flag & SD_OBJECT_TRANSFORM_APPLIED)) {
const Transform tfm = object_get_transform(kg, sd);
P = transform_point(&tfm, P);
}
return P;
# else /* __INTERSECTION_REFINE__ */
return P + D * t;
# endif /* __INTERSECTION_REFINE__ */
# endif
}
#endif /* __BVH_LOCAL__ */
/* Ray intersection. We simply compute the vertex positions at the given ray
* time and do a ray intersection with the resulting triangle.
*/
ccl_device_inline bool motion_triangle_intersect(KernelGlobals kg,
ccl_private Intersection *isect,
float3 P,
float3 dir,
float tmax,
float time,
uint visibility,
int object,
int prim_addr)
{
/* Primitive index for vertex location lookup. */
int prim = kernel_tex_fetch(__prim_index, prim_addr);
int fobject = (object == OBJECT_NONE) ? kernel_tex_fetch(__prim_object, prim_addr) : object;
/* Get vertex locations for intersection. */
float3 verts[3];
motion_triangle_vertices(kg, fobject, prim, time, verts);
/* Ray-triangle intersection, unoptimized. */
float t, u, v;
if (ray_triangle_intersect(P,
dir,
tmax,
#if defined(__KERNEL_SSE2__) && defined(__KERNEL_SSE__)
(ssef *)verts,
#else
verts[0],
verts[1],
verts[2],
#endif
&u,
&v,
&t)) {
#ifdef __VISIBILITY_FLAG__
/* Visibility flag test. we do it here under the assumption
* that most triangles are culled by node flags.
*/
if (kernel_tex_fetch(__prim_visibility, prim_addr) & visibility)
#endif
{
isect->t = t;
isect->u = u;
isect->v = v;
isect->prim = prim;
isect->object = (object == OBJECT_NONE) ? kernel_tex_fetch(__prim_object, prim_addr) :
object;
isect->type = PRIMITIVE_MOTION_TRIANGLE;
return true;
}
}
return false;
}
/* Special ray intersection routines for local intersections. In that case we
* only want to intersect with primitives in the same object, and if case of
* multiple hits we pick a single random primitive as the intersection point.
* Returns whether traversal should be stopped.
*/
#ifdef __BVH_LOCAL__
ccl_device_inline bool motion_triangle_intersect_local(KernelGlobals kg,
ccl_private LocalIntersection *local_isect,
float3 P,
float3 dir,
float time,
int object,
int local_object,
int prim_addr,
float tmax,
ccl_private uint *lcg_state,
int max_hits)
{
/* Only intersect with matching object, for instanced objects we
* already know we are only intersecting the right object. */
if (object == OBJECT_NONE) {
if (kernel_tex_fetch(__prim_object, prim_addr) != local_object) {
return false;
}
}
/* Primitive index for vertex location lookup. */
int prim = kernel_tex_fetch(__prim_index, prim_addr);
/* Get vertex locations for intersection. */
float3 verts[3];
motion_triangle_vertices(kg, local_object, prim, time, verts);
/* Ray-triangle intersection, unoptimized. */
float t, u, v;
if (!ray_triangle_intersect(P,
dir,
tmax,
# if defined(__KERNEL_SSE2__) && defined(__KERNEL_SSE__)
(ssef *)verts,
# else
verts[0],
verts[1],
verts[2],
# endif
&u,
&v,
&t)) {
return false;
}
/* If no actual hit information is requested, just return here. */
if (max_hits == 0) {
return true;
}
int hit;
if (lcg_state) {
/* Record up to max_hits intersections. */
for (int i = min(max_hits, local_isect->num_hits) - 1; i >= 0; --i) {
if (local_isect->hits[i].t == t) {
return false;
}
}
local_isect->num_hits++;
if (local_isect->num_hits <= max_hits) {
hit = local_isect->num_hits - 1;
}
else {
/* Reservoir sampling: if we are at the maximum number of
* hits, randomly replace element or skip it.
*/
hit = lcg_step_uint(lcg_state) % local_isect->num_hits;
if (hit >= max_hits)
return false;
}
}
else {
/* Record closest intersection only. */
if (local_isect->num_hits && t > local_isect->hits[0].t) {
return false;
}
hit = 0;
local_isect->num_hits = 1;
}
/* Record intersection. */
ccl_private Intersection *isect = &local_isect->hits[hit];
isect->t = t;
isect->u = u;
isect->v = v;
isect->prim = prim;
isect->object = local_object;
isect->type = PRIMITIVE_MOTION_TRIANGLE;
/* Record geometric normal. */
local_isect->Ng[hit] = normalize(cross(verts[1] - verts[0], verts[2] - verts[0]));
return false;
}
#endif /* __BVH_LOCAL__ */
CCL_NAMESPACE_END