blender/intern/cycles/util/util_transform.cpp
Brecht Van Lommel d08b06f773 Cycles: motion blur is now curved and passes exactly through the midpoint.
Previously it would only interpolate between the previous and next frame,
which meant it might not hit the current frame position.
2012-10-17 12:55:23 +00:00

258 lines
6.5 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.
*/
/*
* Adapted from code with license:
*
* Copyright (c) 2002, Industrial Light & Magic, a division of Lucas
* Digital Ltd. LLC. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Industrial Light & Magic nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "util_math.h"
#include "util_transform.h"
CCL_NAMESPACE_BEGIN
/* Transform Inverse */
static bool transform_matrix4_gj_inverse(float R[][4], float M[][4])
{
/* forward elimination */
for(int i = 0; i < 4; i++) {
int pivot = i;
float pivotsize = M[i][i];
if(pivotsize < 0)
pivotsize = -pivotsize;
for(int j = i + 1; j < 4; j++) {
float tmp = M[j][i];
if(tmp < 0)
tmp = -tmp;
if(tmp > pivotsize) {
pivot = j;
pivotsize = tmp;
}
}
if(pivotsize == 0)
return false;
if(pivot != i) {
for(int j = 0; j < 4; j++) {
float tmp;
tmp = M[i][j];
M[i][j] = M[pivot][j];
M[pivot][j] = tmp;
tmp = R[i][j];
R[i][j] = R[pivot][j];
R[pivot][j] = tmp;
}
}
for(int j = i + 1; j < 4; j++) {
float f = M[j][i] / M[i][i];
for(int k = 0; k < 4; k++) {
M[j][k] -= f*M[i][k];
R[j][k] -= f*R[i][k];
}
}
}
/* backward substitution */
for(int i = 3; i >= 0; --i) {
float f;
if((f = M[i][i]) == 0)
return false;
for(int j = 0; j < 4; j++) {
M[i][j] /= f;
R[i][j] /= f;
}
for(int j = 0; j < i; j++) {
f = M[j][i];
for(int k = 0; k < 4; k++) {
M[j][k] -= f*M[i][k];
R[j][k] -= f*R[i][k];
}
}
}
return true;
}
Transform transform_inverse(const Transform& tfm)
{
Transform tfmR = transform_identity();
float M[4][4], R[4][4];
memcpy(R, &tfmR, sizeof(R));
memcpy(M, &tfm, sizeof(M));
if(!transform_matrix4_gj_inverse(R, M)) {
/* matrix is degenerate (e.g. 0 scale on some axis), ideally we should
* never be in this situation, but try to invert it anyway with tweak */
M[0][0] += 1e-8f;
M[1][1] += 1e-8f;
M[2][2] += 1e-8f;
if(!transform_matrix4_gj_inverse(R, M))
return transform_identity();
}
memcpy(&tfmR, R, sizeof(R));
return tfmR;
}
/* Motion Transform */
static float4 transform_to_quat(const Transform& tfm)
{
double trace = tfm[0][0] + tfm[1][1] + tfm[2][2];
float4 qt;
if(trace > 0.0) {
double s = sqrt(trace + 1.0);
qt.w = (float)(s/2.0);
s = 0.5/s;
qt.x = (float)((double)(tfm[2][1] - tfm[1][2]) * s);
qt.y = (float)((double)(tfm[0][2] - tfm[2][0]) * s);
qt.z = (float)((double)(tfm[1][0] - tfm[0][1]) * s);
}
else {
int i = 0;
if(tfm[1][1] > tfm[i][i])
i = 1;
if(tfm[2][2] > tfm[i][i])
i = 2;
int j = (i + 1)%3;
int k = (j + 1)%3;
double s = sqrt((double)(tfm[i][i] - (tfm[j][j] + tfm[k][k])) + 1.0);
double q[3];
q[i] = s * 0.5;
if(s != 0.0)
s = 0.5/s;
double w = (double)(tfm[k][j] - tfm[j][k]) * s;
q[j] = (double)(tfm[j][i] + tfm[i][j]) * s;
q[k] = (double)(tfm[k][i] + tfm[i][k]) * s;
qt.x = (float)q[0];
qt.y = (float)q[1];
qt.z = (float)q[2];
qt.w = (float)w;
}
return qt;
}
static void transform_decompose(Transform *decomp, const Transform *tfm)
{
/* extract translation */
decomp->y = make_float4(tfm->x.w, tfm->y.w, tfm->z.w, 0.0f);
/* extract rotation */
Transform M = *tfm;
M.x.w = 0.0f; M.y.w = 0.0f; M.z.w = 0.0f; M.w.w = 1.0f;
Transform R = M;
float norm;
int iteration = 0;
do {
Transform Rnext;
Transform Rit = transform_inverse(transform_transpose(R));
for(int i = 0; i < 4; i++)
for(int j = 0; j < 4; j++)
Rnext[i][j] = 0.5f * (R[i][j] + Rit[i][j]);
norm = 0.0f;
for(int i = 0; i < 3; i++) {
norm = max(norm,
fabsf(R[i][0] - Rnext[i][0]) +
fabsf(R[i][1] - Rnext[i][1]) +
fabsf(R[i][2] - Rnext[i][2]));
}
R = Rnext;
iteration++;
} while(iteration < 100 && norm > 1e-4f);
if(transform_negative_scale(R))
R = R * transform_scale(-1.0f, -1.0f, -1.0f); /* todo: test scale */
decomp->x = transform_to_quat(R);
/* extract scale and pack it */
Transform scale = transform_inverse(R) * M;
decomp->y.w = scale.x.x;
decomp->z = make_float4(scale.x.y, scale.x.z, scale.y.x, scale.y.y);
decomp->w = make_float4(scale.y.z, scale.z.x, scale.z.y, scale.z.z);
}
void transform_motion_decompose(MotionTransform *decomp, const MotionTransform *motion, const Transform *mid)
{
transform_decompose(&decomp->pre, &motion->pre);
transform_decompose(&decomp->mid, mid);
transform_decompose(&decomp->post, &motion->post);
}
CCL_NAMESPACE_END