Welcome to mirror list, hosted at ThFree Co, Russian Federation.

blender_object.cpp « blender « cycles « intern - git.blender.org/blender.git - Unnamed repository; edit this file 'description' to name the repository.
summaryrefslogtreecommitdiff
blob: ed01d7289316f532ef93f41d33dd201dfe2893f2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
/*
 * Copyright 2011-2013 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.
 */

#include "render/camera.h"
#include "render/integrator.h"
#include "render/graph.h"
#include "render/light.h"
#include "render/mesh.h"
#include "render/object.h"
#include "render/scene.h"
#include "render/nodes.h"
#include "render/particles.h"
#include "render/shader.h"

#include "blender/blender_object_cull.h"
#include "blender/blender_sync.h"
#include "blender/blender_util.h"

#include "util/util_foreach.h"
#include "util/util_hash.h"
#include "util/util_logging.h"

CCL_NAMESPACE_BEGIN

/* Utilities */

bool BlenderSync::BKE_object_is_modified(BL::Object& b_ob)
{
	/* test if we can instance or if the object is modified */
	if(b_ob.type() == BL::Object::type_META) {
		/* multi-user and dupli metaballs are fused, can't instance */
		return true;
	}
	else if(ccl::BKE_object_is_modified(b_ob, b_scene, preview)) {
		/* modifiers */
		return true;
	}
	else {
		/* object level material links */
		BL::Object::material_slots_iterator slot;
		for(b_ob.material_slots.begin(slot); slot != b_ob.material_slots.end(); ++slot)
			if(slot->link() == BL::MaterialSlot::link_OBJECT)
				return true;
	}

	return false;
}

bool BlenderSync::object_is_mesh(BL::Object& b_ob)
{
	BL::ID b_ob_data = b_ob.data();

	if(!b_ob_data) {
		return false;
	}

	if(b_ob.type() == BL::Object::type_CURVE) {
		/* Skip exporting curves without faces, overhead can be
		 * significant if there are many for path animation. */
		BL::Curve b_curve(b_ob.data());

		return (b_curve.bevel_object() ||
		        b_curve.extrude() != 0.0f ||
		        b_curve.bevel_depth() != 0.0f ||
		        b_curve.dimensions() == BL::Curve::dimensions_2D ||
		        b_ob.modifiers.length());
	}
	else {
		return (b_ob_data.is_a(&RNA_Mesh) ||
		        b_ob_data.is_a(&RNA_Curve) ||
		        b_ob_data.is_a(&RNA_MetaBall));
	}
}

bool BlenderSync::object_is_light(BL::Object& b_ob)
{
	BL::ID b_ob_data = b_ob.data();

	return (b_ob_data && b_ob_data.is_a(&RNA_Light));
}

static uint object_ray_visibility(BL::Object& b_ob)
{
	PointerRNA cvisibility = RNA_pointer_get(&b_ob.ptr, "cycles_visibility");
	uint flag = 0;

	flag |= get_boolean(cvisibility, "camera")? PATH_RAY_CAMERA: 0;
	flag |= get_boolean(cvisibility, "diffuse")? PATH_RAY_DIFFUSE: 0;
	flag |= get_boolean(cvisibility, "glossy")? PATH_RAY_GLOSSY: 0;
	flag |= get_boolean(cvisibility, "transmission")? PATH_RAY_TRANSMIT: 0;
	flag |= get_boolean(cvisibility, "shadow")? PATH_RAY_SHADOW: 0;
	flag |= get_boolean(cvisibility, "scatter")? PATH_RAY_VOLUME_SCATTER: 0;

	return flag;
}

/* Light */

void BlenderSync::sync_light(BL::Object& b_parent,
                             int persistent_id[OBJECT_PERSISTENT_ID_SIZE],
                             BL::Object& b_ob,
                             BL::Object& b_ob_instance,
                             int random_id,
                             Transform& tfm,
                             bool *use_portal)
{
	/* test if we need to sync */
	Light *light;
	ObjectKey key(b_parent, persistent_id, b_ob_instance);

	if(!light_map.sync(&light, b_ob, b_parent, key)) {
		if(light->is_portal)
			*use_portal = true;
		return;
	}

	BL::Light b_light(b_ob.data());

	/* type */
	switch(b_light.type()) {
		case BL::Light::type_POINT: {
			BL::PointLight b_point_light(b_light);
			light->size = b_point_light.shadow_soft_size();
			light->type = LIGHT_POINT;
			break;
		}
		case BL::Light::type_SPOT: {
			BL::SpotLight b_spot_light(b_light);
			light->size = b_spot_light.shadow_soft_size();
			light->type = LIGHT_SPOT;
			light->spot_angle = b_spot_light.spot_size();
			light->spot_smooth = b_spot_light.spot_blend();
			break;
		}
		case BL::Light::type_HEMI: {
			light->type = LIGHT_DISTANT;
			light->size = 0.0f;
			break;
		}
		case BL::Light::type_SUN: {
			BL::SunLight b_sun_light(b_light);
			light->size = b_sun_light.shadow_soft_size();
			light->type = LIGHT_DISTANT;
			break;
		}
		case BL::Light::type_AREA: {
			BL::AreaLight b_area_light(b_light);
			light->size = 1.0f;
			light->axisu = transform_get_column(&tfm, 0);
			light->axisv = transform_get_column(&tfm, 1);
			light->sizeu = b_area_light.size();
			switch(b_area_light.shape()) {
				case BL::AreaLight::shape_SQUARE:
					light->sizev = light->sizeu;
					light->round = false;
					break;
				case BL::AreaLight::shape_RECTANGLE:
					light->sizev = b_area_light.size_y();
					light->round = false;
					break;
				case BL::AreaLight::shape_DISK:
					light->sizev = light->sizeu;
					light->round = true;
					break;
				case BL::AreaLight::shape_ELLIPSE:
					light->sizev = b_area_light.size_y();
					light->round = true;
					break;
			}
			light->type = LIGHT_AREA;
			break;
		}
	}

	/* location and (inverted!) direction */
	light->co = transform_get_column(&tfm, 3);
	light->dir = -transform_get_column(&tfm, 2);
	light->tfm = tfm;

	/* shader */
	vector<Shader*> used_shaders;
	find_shader(b_light, used_shaders, scene->default_light);
	light->shader = used_shaders[0];

	/* shadow */
	PointerRNA cscene = RNA_pointer_get(&b_scene.ptr, "cycles");
	PointerRNA clight = RNA_pointer_get(&b_light.ptr, "cycles");
	light->cast_shadow = get_boolean(clight, "cast_shadow");
	light->use_mis = get_boolean(clight, "use_multiple_importance_sampling");

	int samples = get_int(clight, "samples");
	if(get_boolean(cscene, "use_square_samples"))
		light->samples = samples * samples;
	else
		light->samples = samples;

	light->max_bounces = get_int(clight, "max_bounces");

	if(b_ob != b_ob_instance) {
		light->random_id = random_id;
	}
	else {
		light->random_id = hash_int_2d(hash_string(b_ob.name().c_str()), 0);
	}

	if(light->type == LIGHT_AREA)
		light->is_portal = get_boolean(clight, "is_portal");
	else
		light->is_portal = false;

	if(light->is_portal)
		*use_portal = true;

	/* visibility */
	uint visibility = object_ray_visibility(b_ob);
	light->use_diffuse = (visibility & PATH_RAY_DIFFUSE) != 0;
	light->use_glossy = (visibility & PATH_RAY_GLOSSY) != 0;
	light->use_transmission = (visibility & PATH_RAY_TRANSMIT) != 0;
	light->use_scatter = (visibility & PATH_RAY_VOLUME_SCATTER) != 0;

	/* tag */
	light->tag_update(scene);
}

void BlenderSync::sync_background_light(bool use_portal)
{
	BL::World b_world = b_scene.world();

	if(b_world) {
		PointerRNA cscene = RNA_pointer_get(&b_scene.ptr, "cycles");
		PointerRNA cworld = RNA_pointer_get(&b_world.ptr, "cycles");

		enum SamplingMethod {
			SAMPLING_NONE = 0,
			SAMPLING_AUTOMATIC,
			SAMPLING_MANUAL,
			SAMPLING_NUM
		};
		int sampling_method = get_enum(cworld, "sampling_method", SAMPLING_NUM, SAMPLING_AUTOMATIC);
		bool sample_as_light = (sampling_method != SAMPLING_NONE);

		if(sample_as_light || use_portal) {
			/* test if we need to sync */
			Light *light;
			ObjectKey key(b_world, 0, b_world);

			if(light_map.sync(&light, b_world, b_world, key) ||
			    world_recalc ||
			    b_world.ptr.data != world_map)
			{
				light->type = LIGHT_BACKGROUND;
				if(sampling_method == SAMPLING_MANUAL) {
					light->map_resolution = get_int(cworld, "sample_map_resolution");
				}
				else {
					light->map_resolution = 0;
				}
				light->shader = scene->default_background;
				light->use_mis = sample_as_light;
				light->max_bounces = get_int(cworld, "max_bounces");

				int samples = get_int(cworld, "samples");
				if(get_boolean(cscene, "use_square_samples"))
					light->samples = samples * samples;
				else
					light->samples = samples;

				light->tag_update(scene);
				light_map.set_recalc(b_world);
			}
		}
	}

	world_map = b_world.ptr.data;
	world_recalc = false;
}

/* Object */

Object *BlenderSync::sync_object(BL::Depsgraph& b_depsgraph,
                                 BL::DepsgraphObjectInstance& b_instance,
                                 uint layer_flag,
                                 float motion_time,
                                 bool hide_tris,
                                 BlenderObjectCulling& culling,
                                 bool *use_portal)
{
	const bool is_instance = b_instance.is_instance();
	BL::Object b_ob = b_instance.object();
	BL::Object b_parent = is_instance ? b_instance.parent()
	                                  : b_instance.object();
	BL::Object b_ob_instance = is_instance ? b_instance.instance_object()
	                                       : b_ob;
	const bool motion = motion_time != 0.0f;
	/*const*/ Transform tfm = get_transform(b_ob.matrix_world());
	int *persistent_id = NULL;
	BL::Array<int, OBJECT_PERSISTENT_ID_SIZE> persistent_id_array;
	if(is_instance) {
		persistent_id_array = b_instance.persistent_id();
		persistent_id = persistent_id_array.data;
	}

	/* light is handled separately */
	if(object_is_light(b_ob)) {
		/* don't use lights for excluded layers used as mask layer */
		if(!motion && !((layer_flag & view_layer.holdout_layer) &&
		                (layer_flag & view_layer.exclude_layer)))
		{
			sync_light(b_parent,
			           persistent_id,
			           b_ob,
			           b_ob_instance,
			           is_instance ? b_instance.random_id() : 0,
			           tfm,
			           use_portal);
		}

		return NULL;
	}

	/* only interested in object that we can create meshes from */
	if(!object_is_mesh(b_ob)) {
		return NULL;
	}

	/* Perform object culling. */
	if(culling.test(scene, b_ob, tfm)) {
		return NULL;
	}

	/* Visibility flags for both parent and child. */
	PointerRNA cobject = RNA_pointer_get(&b_ob.ptr, "cycles");
	bool use_holdout = (layer_flag & view_layer.holdout_layer) != 0 ||
	                   get_boolean(cobject, "is_holdout");
	uint visibility = object_ray_visibility(b_ob) & PATH_RAY_ALL_VISIBILITY;

	if(b_parent.ptr.data != b_ob.ptr.data) {
		visibility &= object_ray_visibility(b_parent);
	}

	/* Make holdout objects on excluded layer invisible for non-camera rays. */
	if(use_holdout && (layer_flag & view_layer.exclude_layer)) {
		visibility &= ~(PATH_RAY_ALL_VISIBILITY - PATH_RAY_CAMERA);
	}

	/* Hide objects not on render layer from camera rays. */
	if(!(layer_flag & view_layer.layer)) {
		visibility &= ~PATH_RAY_CAMERA;
	}

	/* Don't export completely invisible objects. */
	if(visibility == 0) {
		return NULL;
	}

	/* key to lookup object */
	ObjectKey key(b_parent, persistent_id, b_ob_instance);
	Object *object;

	/* motion vector case */
	if(motion) {
		object = object_map.find(key);

		if(object && object->use_motion()) {
			/* Set transform at matching motion time step. */
			int time_index = object->motion_step(motion_time);
			if(time_index >= 0) {
				object->motion[time_index] = tfm;
			}

			/* mesh deformation */
			if(object->mesh)
				sync_mesh_motion(b_depsgraph, b_ob, object, motion_time);
		}

		return object;
	}

	/* test if we need to sync */
	bool object_updated = false;

	if(object_map.sync(&object, b_ob, b_parent, key))
		object_updated = true;

	/* mesh sync */
	object->mesh = sync_mesh(b_depsgraph, b_ob, b_ob_instance, object_updated, hide_tris);

	/* special case not tracked by object update flags */

	/* holdout */
	if(use_holdout != object->use_holdout) {
		object->use_holdout = use_holdout;
		scene->object_manager->tag_update(scene);
		object_updated = true;
	}

	if(visibility != object->visibility) {
		object->visibility = visibility;
		object_updated = true;
	}

	bool is_shadow_catcher = get_boolean(cobject, "is_shadow_catcher");
	if(is_shadow_catcher != object->is_shadow_catcher) {
		object->is_shadow_catcher = is_shadow_catcher;
		object_updated = true;
	}

	/* object sync
	 * transform comparison should not be needed, but duplis don't work perfect
	 * in the depsgraph and may not signal changes, so this is a workaround */
	if(object_updated || (object->mesh && object->mesh->need_update) || tfm != object->tfm) {
		object->name = b_ob.name().c_str();
		object->pass_id = b_ob.pass_index();
		object->tfm = tfm;
		object->motion.clear();

		/* motion blur */
		Scene::MotionType need_motion = scene->need_motion();
		if(need_motion != Scene::MOTION_NONE && object->mesh) {
			Mesh *mesh = object->mesh;
			mesh->use_motion_blur = false;
			mesh->motion_steps = 0;

			uint motion_steps;

			if(scene->need_motion() == Scene::MOTION_BLUR) {
				motion_steps = object_motion_steps(b_parent, b_ob);
				if(motion_steps && object_use_deform_motion(b_parent, b_ob)) {
					mesh->motion_steps = motion_steps;
					mesh->use_motion_blur = true;
				}
			}
			else {
				motion_steps = 3;
				mesh->motion_steps = motion_steps;
			}

			object->motion.clear();
			object->motion.resize(motion_steps, transform_empty());

			if(motion_steps) {
				object->motion[motion_steps/2] = tfm;

				for(size_t step = 0; step < motion_steps; step++) {
					motion_times.insert(object->motion_time(step));
				}
			}
		}

		/* dupli texture coordinates and random_id */
		if(is_instance) {
			object->dupli_generated = 0.5f*get_float3(b_instance.orco()) - make_float3(0.5f, 0.5f, 0.5f);
			object->dupli_uv = get_float2(b_instance.uv());
			object->random_id = b_instance.random_id();

			/* Sync possible particle data. */
			sync_dupli_particle(b_ob, b_instance, object);
		}
		else {
			object->dupli_generated = make_float3(0.0f, 0.0f, 0.0f);
			object->dupli_uv = make_float2(0.0f, 0.0f);
			object->random_id =  hash_int_2d(hash_string(object->name.c_str()), 0);
		}

		object->tag_update(scene);
	}

	return object;
}

static bool object_render_hide_original(BL::Object::type_enum ob_type,
                                        BL::Object::dupli_type_enum dupli_type)
{
	/* metaball exception, they duplicate self */
	if(ob_type == BL::Object::type_META)
		return false;

	return (dupli_type == BL::Object::dupli_type_VERTS ||
	        dupli_type == BL::Object::dupli_type_FACES ||
	        dupli_type == BL::Object::dupli_type_FRAMES);
}

static bool object_render_hide(BL::Object& b_ob,
                               bool top_level,
                               bool parent_hide,
                               bool& hide_triangles,
                               BL::Depsgraph::mode_enum depsgraph_mode)
{
	/* check if we should render or hide particle emitter */
	BL::Object::particle_systems_iterator b_psys;

	bool hair_present = false;
	bool has_particles = false;
	bool show_emitter = false;
	bool hide_emitter = false;
	bool hide_as_dupli_parent = false;
	bool hide_as_dupli_child_original = false;

	for(b_ob.particle_systems.begin(b_psys); b_psys != b_ob.particle_systems.end(); ++b_psys) {
		if((b_psys->settings().render_type() == BL::ParticleSettings::render_type_PATH) &&
		   (b_psys->settings().type()==BL::ParticleSettings::type_HAIR))
			hair_present = true;
		has_particles = true;
	}

	/* Both mode_PREVIEW and mode_VIEWPORT are treated the same here.*/
	const bool show_duplicator = depsgraph_mode == BL::Depsgraph::mode_RENDER
	                             ? b_ob.show_duplicator_for_render()
	                             : b_ob.show_duplicator_for_viewport();

	if(has_particles) {
		show_emitter = show_duplicator;
		hide_emitter = !show_emitter;
	} else if(b_ob.is_duplicator()) {
		if(top_level || show_duplicator) {
			hide_as_dupli_parent = true;
		}
	}

	/* hide original object for duplis */
	BL::Object parent = b_ob.parent();
	while(parent) {
		if(object_render_hide_original(b_ob.type(),
		                               parent.dupli_type()))
		{
			if(parent_hide) {
				hide_as_dupli_child_original = true;
				break;
			}
		}
		parent = parent.parent();
	}

	hide_triangles = hide_emitter;

	if(show_emitter) {
		return false;
	}
	else if(hair_present) {
		return hide_as_dupli_child_original;
	}
	else {
		return (hide_as_dupli_parent || hide_as_dupli_child_original);
	}
}

/* Object Loop */

void BlenderSync::sync_objects(BL::Depsgraph& b_depsgraph, float motion_time)
{
	/* layer data */
	bool motion = motion_time != 0.0f;

	if(!motion) {
		/* prepare for sync */
		light_map.pre_sync();
		mesh_map.pre_sync();
		object_map.pre_sync();
		particle_system_map.pre_sync();
		motion_times.clear();
	}
	else {
		mesh_motion_synced.clear();
	}

	/* initialize culling */
	BlenderObjectCulling culling(scene, b_scene);

	/* object loop */
	bool cancel = false;
	bool use_portal = false;

	BL::Depsgraph::mode_enum depsgraph_mode = b_depsgraph.mode();

	BL::Depsgraph::object_instances_iterator b_instance_iter;
	for(b_depsgraph.object_instances.begin(b_instance_iter);
	    b_instance_iter != b_depsgraph.object_instances.end() && !cancel;
	    ++b_instance_iter)
	{
		BL::DepsgraphObjectInstance b_instance = *b_instance_iter;
		BL::Object b_ob = b_instance.object();

		progress.set_sync_status("Synchronizing object", b_ob.name());

		/* load per-object culling data */
		culling.init_object(scene, b_ob);

		/* test if object needs to be hidden */
		bool hide_tris;

		 if(!object_render_hide(b_ob, true, true, hide_tris, depsgraph_mode)) {
			/* object itself */
			sync_object(b_depsgraph,
			            b_instance,
			            ~(0), /* until we get rid of layers */
			            motion_time,
			            hide_tris,
			            culling,
			            &use_portal);
		 }

		cancel = progress.get_cancel();
	}

	progress.set_sync_status("");

	if(!cancel && !motion) {
		sync_background_light(use_portal);

		/* handle removed data and modified pointers */
		if(light_map.post_sync())
			scene->light_manager->tag_update(scene);
		if(mesh_map.post_sync())
			scene->mesh_manager->tag_update(scene);
		if(object_map.post_sync())
			scene->object_manager->tag_update(scene);
		if(particle_system_map.post_sync())
			scene->particle_system_manager->tag_update(scene);
	}

	if(motion)
		mesh_motion_synced.clear();
}

void BlenderSync::sync_motion(BL::RenderSettings& b_render,
                              BL::Depsgraph& b_depsgraph,
                              BL::Object& b_override,
                              int width, int height,
                              void **python_thread_state)
{
	if(scene->need_motion() == Scene::MOTION_NONE)
		return;

	/* get camera object here to deal with camera switch */
	BL::Object b_cam = b_scene.camera();
	if(b_override)
		b_cam = b_override;

	Camera prevcam = *(scene->camera);

	int frame_center = b_scene.frame_current();
	float subframe_center = b_scene.frame_subframe();
	float frame_center_delta = 0.0f;

	if(scene->need_motion() != Scene::MOTION_PASS &&
	   scene->camera->motion_position != Camera::MOTION_POSITION_CENTER)
	{
		float shuttertime = scene->camera->shuttertime;
		if(scene->camera->motion_position == Camera::MOTION_POSITION_END) {
			frame_center_delta = -shuttertime * 0.5f;
		}
		else {
			assert(scene->camera->motion_position == Camera::MOTION_POSITION_START);
			frame_center_delta = shuttertime * 0.5f;
		}

		float time = frame_center + subframe_center + frame_center_delta;
		int frame = (int)floorf(time);
		float subframe = time - frame;
		python_thread_state_restore(python_thread_state);
		b_engine.frame_set(frame, subframe);
		python_thread_state_save(python_thread_state);
		sync_camera_motion(b_render, b_cam, width, height, 0.0f);
		sync_objects(b_depsgraph, 0.0f);
	}

	/* always sample these times for camera motion */
	motion_times.insert(-1.0f);
	motion_times.insert(1.0f);

	/* note iteration over motion_times set happens in sorted order */
	foreach(float relative_time, motion_times) {
		/* center time is already handled. */
		if(relative_time == 0.0f) {
			continue;
		}

		VLOG(1) << "Synchronizing motion for the relative time "
		        << relative_time << ".";

		/* fixed shutter time to get previous and next frame for motion pass */
		float shuttertime = scene->motion_shutter_time();

		/* compute frame and subframe time */
		float time = frame_center + subframe_center + frame_center_delta + relative_time * shuttertime * 0.5f;
		int frame = (int)floorf(time);
		float subframe = time - frame;

		/* change frame */
		python_thread_state_restore(python_thread_state);
		b_engine.frame_set(frame, subframe);
		python_thread_state_save(python_thread_state);

		/* sync camera, only supports two times at the moment */
		if(relative_time == -1.0f || relative_time == 1.0f) {
			sync_camera_motion(b_render,
			                   b_cam,
			                   width, height,
			                   relative_time);
		}

		/* sync object */
		sync_objects(b_depsgraph, relative_time);
	}

	/* we need to set the python thread state again because this
	 * function assumes it is being executed from python and will
	 * try to save the thread state */
	python_thread_state_restore(python_thread_state);
	b_engine.frame_set(frame_center, subframe_center);
	python_thread_state_save(python_thread_state);

	/* tag camera for motion update */
	if(scene->camera->motion_modified(prevcam))
		scene->camera->tag_update();
}

CCL_NAMESPACE_END