Cycles: Implement rolling shutter effect

This is an attempt to emulate real CMOS cameras which reads sensor by scanlines
and hence different scanlines are sampled at a different moment in time, which
causes so called rolling shutter effect. This effect will, for example, make
vertical straight lines being curved when doing horizontal camera pan.

This is controlled by the Shutter Type option in the Motion Blur panel.

Additionally, since scanline sampling is not instantaneous it's possible to have
motion blur on top of rolling shutter.

This is controlled by the Rolling Shutter Time slider which controls balance
between pure rolling shutter effect and pure motion blur effect.

Reviewers: brecht, juicyfruit, dingto, keir

Differential Revision: https://developer.blender.org/D1624

1 files changed, 21 insertions, 0 deletions

diff --git a/intern/cycles/blender/blender_camera.cpp b/intern/cycles/blender/blender_camera.cpp
index cde3840b796..5f2e0762964 100644
--- a/intern/cycles/blender/blender_camera.cpp
+++ b/intern/cycles/blender/blender_camera.cpp
@@ -39,6 +39,9 @@ struct BlenderCamera {
 	Camera::MotionPosition motion_position;
 	float shutter_curve[RAMP_TABLE_SIZE];
 
+	Camera::RollingShutterType rolling_shutter_type;
+	float rolling_shutter_duration;
+
 	float aperturesize;
 	uint apertureblades;
 	float aperturerotation;
@@ -86,6 +89,8 @@ static void blender_camera_init(BlenderCamera *bcam, BL::RenderSettings b_render
 	bcam->sensor_fit = BlenderCamera::AUTO;
 	bcam->shuttertime = 1.0f;
 	bcam->motion_position = Camera::MOTION_POSITION_CENTER;
+	bcam->rolling_shutter_type = Camera::ROLLING_SHUTTER_NONE;
+	bcam->rolling_shutter_duration = 0.1f;
 	bcam->border.right = 1.0f;
 	bcam->border.top = 1.0f;
 	bcam->pano_viewplane.right = 1.0f;
@@ -418,6 +423,9 @@ static void blender_camera_sync(Camera *cam, BlenderCamera *bcam, int width, int
 	cam->fov_post = cam->fov;
 	cam->motion_position = bcam->motion_position;
 
+	cam->rolling_shutter_type = bcam->rolling_shutter_type;
+	cam->rolling_shutter_duration = bcam->rolling_shutter_duration;
+
 	memcpy(cam->shutter_curve, bcam->shutter_curve, sizeof(cam->shutter_curve));
 
 	/* border */
@@ -460,6 +468,19 @@ void BlenderSync::sync_camera(BL::RenderSettings b_render, BL::Object b_override
 			break;
 	}
 
+	switch(RNA_enum_get(&cscene, "rolling_shutter_type")) {
+		case 0:
+			bcam.rolling_shutter_type = Camera::ROLLING_SHUTTER_NONE;
+			break;
+		case 1:
+			bcam.rolling_shutter_type = Camera::ROLLING_SHUTTER_TOP;
+			break;
+		default:
+			bcam.rolling_shutter_type = Camera::ROLLING_SHUTTER_NONE;
+			break;
+	}
+	bcam.rolling_shutter_duration = RNA_float_get(&cscene, "rolling_shutter_duration");
+
 	/* border */
 	if(b_render.use_border()) {
 		bcam.border.left = b_render.border_min_x();