0677e19fa0
The issue here is that originally, the step count for the geometry's motion and the object transform's motion were tied together, so a single variable is used to store that step count. However, when using the velocity attribute, it's possible for the step counts to differ, which will lead to an incorrect interpolated object transform in the kernel. Pull Request: https://projects.blender.org/blender/blender/pulls/133788
71 lines
2.1 KiB
C
71 lines
2.1 KiB
C
/* SPDX-FileCopyrightText: 2021-2022 Blender Foundation
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*
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* SPDX-License-Identifier: Apache-2.0 */
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#pragma once
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#include "kernel/globals.h"
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#include "kernel/bvh/util.h"
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CCL_NAMESPACE_BEGIN
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/* Motion Point Primitive
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*
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* These are stored as regular points, plus extra positions and radii at times
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* other than the frame center. Computing the point at a given ray time is
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* a matter of interpolation of the two steps between which the ray time lies.
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*
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* The extra points are stored as ATTR_STD_MOTION_VERTEX_POSITION.
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*/
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#ifdef __POINTCLOUD__
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ccl_device_inline float4 motion_point_for_step(
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KernelGlobals kg, int offset, const int numverts, const int numsteps, int step, const int prim)
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{
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if (step == numsteps) {
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/* center step: regular key location */
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return kernel_data_fetch(points, prim);
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}
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/* center step is not stored in this array */
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if (step > numsteps) {
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step--;
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}
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offset += step * numverts;
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return kernel_data_fetch(attributes_float4, offset + prim);
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}
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/* return 2 point key locations */
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ccl_device_inline float4 motion_point(KernelGlobals kg,
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const int object,
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const int prim,
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const float time)
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{
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/* get motion info */
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const int numsteps = kernel_data_fetch(objects, object).num_geom_steps;
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const int numverts = kernel_data_fetch(objects, object).numverts;
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/* figure out which steps we need to fetch and their interpolation factor */
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const int maxstep = numsteps * 2;
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const int step = min((int)(time * maxstep), maxstep - 1);
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const float t = time * maxstep - step;
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/* find attribute */
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const int offset = intersection_find_attribute(kg, object, ATTR_STD_MOTION_VERTEX_POSITION);
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kernel_assert(offset != ATTR_STD_NOT_FOUND);
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/* fetch key coordinates */
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const float4 point = motion_point_for_step(kg, offset, numverts, numsteps, step, prim);
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const float4 next_point = motion_point_for_step(kg, offset, numverts, numsteps, step + 1, prim);
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/* interpolate between steps */
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return (1.0f - t) * point + t * next_point;
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}
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#endif
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CCL_NAMESPACE_END
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