f4e4f19af2
- Rename dx/dy -> dfdx/dfdy to match the actual computed quantity - Add template functions to compute dfdx/dfdy on triangles for sharing among different data types - Add documentation to some functions - Some code shuffling that makes it easier to scale dfdx/dfdy in the future - Some other trivial changes
409 lines
15 KiB
C++
409 lines
15 KiB
C++
/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
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*
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* SPDX-License-Identifier: Apache-2.0 */
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/* Triangle Primitive
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*
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* Basic triangle with 3 vertices is used to represent mesh surfaces. For BVH
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* ray intersection we use a precomputed triangle storage to accelerate
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* intersection at the cost of more memory usage */
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#pragma once
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#include "kernel/globals.h"
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#include "kernel/geom/object.h"
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#include "util/color.h"
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CCL_NAMESPACE_BEGIN
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/* Normal on triangle. */
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ccl_device_inline float3 triangle_normal(KernelGlobals kg, ccl_private ShaderData *sd)
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{
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/* load triangle vertices */
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const uint3 tri_vindex = kernel_data_fetch(tri_vindex, sd->prim);
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const float3 v0 = kernel_data_fetch(tri_verts, tri_vindex.x);
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const float3 v1 = kernel_data_fetch(tri_verts, tri_vindex.y);
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const float3 v2 = kernel_data_fetch(tri_verts, tri_vindex.z);
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/* return normal */
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if (object_negative_scale_applied(sd->object_flag)) {
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return normalize(cross(v2 - v0, v1 - v0));
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}
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return normalize(cross(v1 - v0, v2 - v0));
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}
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/* Point and normal on triangle. */
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ccl_device_inline void triangle_point_normal(KernelGlobals kg,
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const int object,
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const int prim,
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const float u,
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const float v,
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ccl_private float3 *P,
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ccl_private float3 *Ng,
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ccl_private int *shader)
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{
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/* load triangle vertices */
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const uint3 tri_vindex = kernel_data_fetch(tri_vindex, prim);
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const float3 v0 = kernel_data_fetch(tri_verts, tri_vindex.x);
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const float3 v1 = kernel_data_fetch(tri_verts, tri_vindex.y);
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const float3 v2 = kernel_data_fetch(tri_verts, tri_vindex.z);
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/* compute point */
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const float w = 1.0f - u - v;
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*P = (w * v0 + u * v1 + v * v2);
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/* get object flags */
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const int object_flag = kernel_data_fetch(object_flag, object);
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/* compute normal */
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if (object_negative_scale_applied(object_flag)) {
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*Ng = normalize(cross(v2 - v0, v1 - v0));
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}
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else {
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*Ng = normalize(cross(v1 - v0, v2 - v0));
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}
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/* shader`*/
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*shader = kernel_data_fetch(tri_shader, prim);
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}
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/* Triangle vertex locations */
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ccl_device_inline void triangle_vertices(KernelGlobals kg, const int prim, float3 P[3])
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{
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const uint3 tri_vindex = kernel_data_fetch(tri_vindex, prim);
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P[0] = kernel_data_fetch(tri_verts, tri_vindex.x);
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P[1] = kernel_data_fetch(tri_verts, tri_vindex.y);
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P[2] = kernel_data_fetch(tri_verts, tri_vindex.z);
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}
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/* Triangle vertex locations and vertex normals */
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ccl_device_inline void triangle_vertices_and_normals(KernelGlobals kg,
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const int prim,
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float3 P[3],
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float3 N[3])
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{
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const uint3 tri_vindex = kernel_data_fetch(tri_vindex, prim);
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P[0] = kernel_data_fetch(tri_verts, tri_vindex.x);
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P[1] = kernel_data_fetch(tri_verts, tri_vindex.y);
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P[2] = kernel_data_fetch(tri_verts, tri_vindex.z);
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N[0] = kernel_data_fetch(tri_vnormal, tri_vindex.x);
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N[1] = kernel_data_fetch(tri_vnormal, tri_vindex.y);
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N[2] = kernel_data_fetch(tri_vnormal, tri_vindex.z);
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}
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/* Interpolate smooth vertex normal from vertices */
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ccl_device_inline float3
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triangle_smooth_normal(KernelGlobals kg, const float3 Ng, const int prim, const float u, float v)
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{
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/* load triangle vertices */
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const uint3 tri_vindex = kernel_data_fetch(tri_vindex, prim);
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const float3 n0 = kernel_data_fetch(tri_vnormal, tri_vindex.x);
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const float3 n1 = kernel_data_fetch(tri_vnormal, tri_vindex.y);
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const float3 n2 = kernel_data_fetch(tri_vnormal, tri_vindex.z);
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const float3 N = safe_normalize((1.0f - u - v) * n0 + u * n1 + v * n2);
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return is_zero(N) ? Ng : N;
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}
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ccl_device_inline float3 triangle_smooth_normal_unnormalized(KernelGlobals kg,
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const ccl_private ShaderData *sd,
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const float3 Ng,
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const int prim,
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const float u,
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float v)
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{
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/* load triangle vertices */
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const uint3 tri_vindex = kernel_data_fetch(tri_vindex, prim);
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float3 n0 = kernel_data_fetch(tri_vnormal, tri_vindex.x);
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float3 n1 = kernel_data_fetch(tri_vnormal, tri_vindex.y);
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float3 n2 = kernel_data_fetch(tri_vnormal, tri_vindex.z);
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/* ensure that the normals are in object space */
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if (sd->object_flag & SD_OBJECT_TRANSFORM_APPLIED) {
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object_inverse_normal_transform(kg, sd, &n0);
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object_inverse_normal_transform(kg, sd, &n1);
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object_inverse_normal_transform(kg, sd, &n2);
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}
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const float3 N = (1.0f - u - v) * n0 + u * n1 + v * n2;
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return is_zero(N) ? Ng : N;
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}
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/* Ray differentials on triangle */
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ccl_device_inline void triangle_dPdudv(KernelGlobals kg,
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const int prim,
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ccl_private float3 *dPdu,
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ccl_private float3 *dPdv)
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{
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/* fetch triangle vertex coordinates */
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const uint3 tri_vindex = kernel_data_fetch(tri_vindex, prim);
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const float3 p0 = kernel_data_fetch(tri_verts, tri_vindex.x);
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const float3 p1 = kernel_data_fetch(tri_verts, tri_vindex.y);
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const float3 p2 = kernel_data_fetch(tri_verts, tri_vindex.z);
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/* compute derivatives of P w.r.t. uv */
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*dPdu = (p1 - p0);
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*dPdv = (p2 - p0);
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}
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/* Partial derivative of f w.r.t. x, namely ∂f/∂x.
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* f is a function of barycentric coordinates u, v, given by
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* f(u, v) = f1 * u + f2 * v + f0 * (1 - u - v),
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* the derivatives are
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* ∂f/∂u = (f1 - f0), ∂f/∂v = (f2 - f0).
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* The partial derivative in x is
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* ∂f/∂x = ∂f/∂u * ∂u/∂x + ∂f/∂v * ∂v/∂x
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* = (f1 - f0) * du.dx + (f2 - f0) * dv.dx. */
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template<typename T>
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ccl_device_inline T triangle_attribute_dfdx(const ccl_private differential &du,
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const ccl_private differential &dv,
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const ccl_private T &f0,
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const ccl_private T &f1,
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const ccl_private T &f2)
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{
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return du.dx * f1 + dv.dx * f2 - (du.dx + dv.dx) * f0;
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}
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/* Partial derivative of f w.r.t. in x, namely ∂f/∂y, similarly computed as ∂f/∂x above. */
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template<typename T>
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ccl_device_inline T triangle_attribute_dfdy(const ccl_private differential &du,
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const ccl_private differential &dv,
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const ccl_private T &f0,
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const ccl_private T &f1,
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const ccl_private T &f2)
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{
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return du.dy * f1 + dv.dy * f2 - (du.dy + dv.dy) * f0;
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}
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/* Read attributes on various triangle elements, and compute the partial derivatives if requested.
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*/
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ccl_device float triangle_attribute_float(KernelGlobals kg,
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const ccl_private ShaderData *sd,
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const AttributeDescriptor desc,
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ccl_private float *dfdx,
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ccl_private float *dfdy)
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{
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if (desc.element & (ATTR_ELEMENT_VERTEX | ATTR_ELEMENT_VERTEX_MOTION | ATTR_ELEMENT_CORNER)) {
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float f0;
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float f1;
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float f2;
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if (desc.element & (ATTR_ELEMENT_VERTEX | ATTR_ELEMENT_VERTEX_MOTION)) {
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const uint3 tri_vindex = kernel_data_fetch(tri_vindex, sd->prim);
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f0 = kernel_data_fetch(attributes_float, desc.offset + tri_vindex.x);
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f1 = kernel_data_fetch(attributes_float, desc.offset + tri_vindex.y);
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f2 = kernel_data_fetch(attributes_float, desc.offset + tri_vindex.z);
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}
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else {
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const int tri = desc.offset + sd->prim * 3;
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f0 = kernel_data_fetch(attributes_float, tri + 0);
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f1 = kernel_data_fetch(attributes_float, tri + 1);
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f2 = kernel_data_fetch(attributes_float, tri + 2);
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}
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#ifdef __RAY_DIFFERENTIALS__
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if (dfdx) {
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*dfdx = triangle_attribute_dfdx(sd->du, sd->dv, f0, f1, f2);
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}
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if (dfdy) {
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*dfdy = triangle_attribute_dfdy(sd->du, sd->dv, f0, f1, f2);
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}
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#endif
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return sd->u * f1 + sd->v * f2 + (1.0f - sd->u - sd->v) * f0;
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}
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#ifdef __RAY_DIFFERENTIALS__
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if (dfdx) {
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*dfdx = 0.0f;
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}
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if (dfdy) {
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*dfdy = 0.0f;
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}
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#endif
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if (desc.element & (ATTR_ELEMENT_FACE | ATTR_ELEMENT_OBJECT | ATTR_ELEMENT_MESH)) {
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const int offset = (desc.element == ATTR_ELEMENT_FACE) ? desc.offset + sd->prim : desc.offset;
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return kernel_data_fetch(attributes_float, offset);
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}
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return 0.0f;
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}
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ccl_device float2 triangle_attribute_float2(KernelGlobals kg,
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const ccl_private ShaderData *sd,
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const AttributeDescriptor desc,
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ccl_private float2 *dfdx,
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ccl_private float2 *dfdy)
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{
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if (desc.element & (ATTR_ELEMENT_VERTEX | ATTR_ELEMENT_VERTEX_MOTION | ATTR_ELEMENT_CORNER)) {
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float2 f0;
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float2 f1;
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float2 f2;
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if (desc.element & (ATTR_ELEMENT_VERTEX | ATTR_ELEMENT_VERTEX_MOTION)) {
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const uint3 tri_vindex = kernel_data_fetch(tri_vindex, sd->prim);
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f0 = kernel_data_fetch(attributes_float2, desc.offset + tri_vindex.x);
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f1 = kernel_data_fetch(attributes_float2, desc.offset + tri_vindex.y);
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f2 = kernel_data_fetch(attributes_float2, desc.offset + tri_vindex.z);
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}
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else {
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const int tri = desc.offset + sd->prim * 3;
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f0 = kernel_data_fetch(attributes_float2, tri + 0);
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f1 = kernel_data_fetch(attributes_float2, tri + 1);
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f2 = kernel_data_fetch(attributes_float2, tri + 2);
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}
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#ifdef __RAY_DIFFERENTIALS__
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if (dfdx) {
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*dfdx = triangle_attribute_dfdx(sd->du, sd->dv, f0, f1, f2);
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}
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if (dfdy) {
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*dfdy = triangle_attribute_dfdy(sd->du, sd->dv, f0, f1, f2);
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}
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#endif
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return sd->u * f1 + sd->v * f2 + (1.0f - sd->u - sd->v) * f0;
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}
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#ifdef __RAY_DIFFERENTIALS__
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if (dfdx) {
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*dfdx = zero_float2();
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}
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if (dfdy) {
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*dfdy = zero_float2();
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}
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#endif
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if (desc.element & (ATTR_ELEMENT_FACE | ATTR_ELEMENT_OBJECT | ATTR_ELEMENT_MESH)) {
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const int offset = (desc.element == ATTR_ELEMENT_FACE) ? desc.offset + sd->prim : desc.offset;
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return kernel_data_fetch(attributes_float2, offset);
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}
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return zero_float2();
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}
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ccl_device float3 triangle_attribute_float3(KernelGlobals kg,
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const ccl_private ShaderData *sd,
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const AttributeDescriptor desc,
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ccl_private float3 *dfdx,
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ccl_private float3 *dfdy)
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{
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if (desc.element & (ATTR_ELEMENT_VERTEX | ATTR_ELEMENT_VERTEX_MOTION | ATTR_ELEMENT_CORNER)) {
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float3 f0;
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float3 f1;
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float3 f2;
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if (desc.element & (ATTR_ELEMENT_VERTEX | ATTR_ELEMENT_VERTEX_MOTION)) {
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const uint3 tri_vindex = kernel_data_fetch(tri_vindex, sd->prim);
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f0 = kernel_data_fetch(attributes_float3, desc.offset + tri_vindex.x);
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f1 = kernel_data_fetch(attributes_float3, desc.offset + tri_vindex.y);
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f2 = kernel_data_fetch(attributes_float3, desc.offset + tri_vindex.z);
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}
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else {
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const int tri = desc.offset + sd->prim * 3;
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f0 = kernel_data_fetch(attributes_float3, tri + 0);
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f1 = kernel_data_fetch(attributes_float3, tri + 1);
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f2 = kernel_data_fetch(attributes_float3, tri + 2);
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}
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#ifdef __RAY_DIFFERENTIALS__
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if (dfdx) {
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*dfdx = triangle_attribute_dfdx(sd->du, sd->dv, f0, f1, f2);
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}
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if (dfdy) {
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*dfdy = triangle_attribute_dfdy(sd->du, sd->dv, f0, f1, f2);
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}
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#endif
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return sd->u * f1 + sd->v * f2 + (1.0f - sd->u - sd->v) * f0;
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}
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#ifdef __RAY_DIFFERENTIALS__
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if (dfdx) {
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*dfdx = zero_float3();
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}
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if (dfdy) {
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*dfdy = zero_float3();
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}
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#endif
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if (desc.element & (ATTR_ELEMENT_FACE | ATTR_ELEMENT_OBJECT | ATTR_ELEMENT_MESH)) {
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const int offset = (desc.element == ATTR_ELEMENT_FACE) ? desc.offset + sd->prim : desc.offset;
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return kernel_data_fetch(attributes_float3, offset);
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}
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return zero_float3();
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}
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ccl_device float4 triangle_attribute_float4(KernelGlobals kg,
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const ccl_private ShaderData *sd,
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const AttributeDescriptor desc,
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ccl_private float4 *dfdx,
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ccl_private float4 *dfdy)
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{
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if (desc.element & (ATTR_ELEMENT_VERTEX | ATTR_ELEMENT_VERTEX_MOTION | ATTR_ELEMENT_CORNER |
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ATTR_ELEMENT_CORNER_BYTE))
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{
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float4 f0;
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float4 f1;
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float4 f2;
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if (desc.element & (ATTR_ELEMENT_VERTEX | ATTR_ELEMENT_VERTEX_MOTION)) {
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const uint3 tri_vindex = kernel_data_fetch(tri_vindex, sd->prim);
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f0 = kernel_data_fetch(attributes_float4, desc.offset + tri_vindex.x);
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f1 = kernel_data_fetch(attributes_float4, desc.offset + tri_vindex.y);
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f2 = kernel_data_fetch(attributes_float4, desc.offset + tri_vindex.z);
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}
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else {
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const int tri = desc.offset + sd->prim * 3;
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if (desc.element == ATTR_ELEMENT_CORNER) {
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f0 = kernel_data_fetch(attributes_float4, tri + 0);
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f1 = kernel_data_fetch(attributes_float4, tri + 1);
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f2 = kernel_data_fetch(attributes_float4, tri + 2);
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}
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else {
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f0 = color_srgb_to_linear_v4(
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color_uchar4_to_float4(kernel_data_fetch(attributes_uchar4, tri + 0)));
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f1 = color_srgb_to_linear_v4(
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color_uchar4_to_float4(kernel_data_fetch(attributes_uchar4, tri + 1)));
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f2 = color_srgb_to_linear_v4(
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color_uchar4_to_float4(kernel_data_fetch(attributes_uchar4, tri + 2)));
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}
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}
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#ifdef __RAY_DIFFERENTIALS__
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if (dfdx) {
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*dfdx = triangle_attribute_dfdx(sd->du, sd->dv, f0, f1, f2);
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}
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if (dfdy) {
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*dfdy = triangle_attribute_dfdy(sd->du, sd->dv, f0, f1, f2);
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}
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#endif
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return sd->u * f1 + sd->v * f2 + (1.0f - sd->u - sd->v) * f0;
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}
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#ifdef __RAY_DIFFERENTIALS__
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if (dfdx) {
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*dfdx = zero_float4();
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}
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if (dfdy) {
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*dfdy = zero_float4();
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}
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#endif
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if (desc.element & (ATTR_ELEMENT_FACE | ATTR_ELEMENT_OBJECT | ATTR_ELEMENT_MESH)) {
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const int offset = (desc.element == ATTR_ELEMENT_FACE) ? desc.offset + sd->prim : desc.offset;
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return kernel_data_fetch(attributes_float4, offset);
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}
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return zero_float4();
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}
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CCL_NAMESPACE_END
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