Cycles: support for camera rendering an environment map with equirectangular

environment map, by enabling the Panorama option in the camera.

http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Camera#Panorama

The focal length or sensor settings are not used, the UI can be tweaked still to
communicate this, also panorama should probably become a proper camera type like
perspective or ortho.

10 files changed, 142 insertions, 58 deletions

diff --git a/intern/cycles/app/cycles_xml.cpp b/intern/cycles/app/cycles_xml.cpp
index 5e4b3da071d..283bdf52e03 100644
--- a/intern/cycles/app/cycles_xml.cpp
+++ b/intern/cycles/app/cycles_xml.cpp
@@ -288,9 +288,11 @@ static void xml_read_camera(const XMLReadState& state, pugi::xml_node node)
 	xml_read_float(&cam->shutterclose, node, "shutterclose");
 
 	if(xml_equal_string(node, "type", "orthographic"))
-		cam->ortho = true;
+		cam->type = CAMERA_ORTHOGRAPHIC;
 	else if(xml_equal_string(node, "type", "perspective"))
-		cam->ortho = false;
+		cam->type = CAMERA_PERSPECTIVE;
+	else if(xml_equal_string(node, "type", "environment"))
+		cam->type = CAMERA_ENVIRONMENT;
 
 	cam->matrix = state.tfm;
 
diff --git a/intern/cycles/blender/blender_camera.cpp b/intern/cycles/blender/blender_camera.cpp
index cbc430d9240..7c9c162f8b1 100644
--- a/intern/cycles/blender/blender_camera.cpp
+++ b/intern/cycles/blender/blender_camera.cpp
@@ -31,7 +31,7 @@ struct BlenderCamera {
 	float nearclip;
 	float farclip;
 
-	bool ortho;
+	CameraType type;
 	float ortho_scale;
 
 	float lens;
@@ -58,6 +58,7 @@ static void blender_camera_init(BlenderCamera *bcam)
 {
 	memset(bcam, 0, sizeof(BlenderCamera));
 
+	bcam->type = CAMERA_PERSPECTIVE;
 	bcam->zoom = 1.0f;
 	bcam->pixelaspect = make_float2(1.0f, 1.0f);
 	bcam->sensor_width = 32.0f;
@@ -91,7 +92,9 @@ static void blender_camera_from_object(BlenderCamera *bcam, BL::Object b_ob)
 		bcam->nearclip = b_camera.clip_start();
 		bcam->farclip = b_camera.clip_end();
 
-		bcam->ortho = (b_camera.type() == BL::Camera::type_ORTHO);
+		bcam->type = (b_camera.type() == BL::Camera::type_ORTHO)? CAMERA_ORTHOGRAPHIC: CAMERA_PERSPECTIVE;
+		if(bcam->type == CAMERA_PERSPECTIVE && b_camera.use_panorama())
+			bcam->type = CAMERA_ENVIRONMENT;
 		bcam->ortho_scale = b_camera.ortho_scale();
 
 		bcam->lens = b_camera.lens();
@@ -159,39 +162,48 @@ static void blender_camera_sync(Camera *cam, BlenderCamera *bcam, int width, int
 	}
 
 	/* modify aspect for orthographic scale */
-	if(bcam->ortho) {
+	if(bcam->type == CAMERA_ORTHOGRAPHIC) {
 		xaspect = xaspect*bcam->ortho_scale/(aspectratio*2.0f);
 		yaspect = yaspect*bcam->ortho_scale/(aspectratio*2.0f);
 		aspectratio = bcam->ortho_scale/2.0f;
 	}
 
-	/* set viewplane */
-	cam->left = -xaspect;
-	cam->right = xaspect;
-	cam->bottom = -yaspect;
-	cam->top = yaspect;
-
-	/* zoom for 3d camera view */
-	cam->left *= bcam->zoom;
-	cam->right *= bcam->zoom;
-	cam->bottom *= bcam->zoom;
-	cam->top *= bcam->zoom;
-
-	/* modify viewplane with camera shift and 3d camera view offset */
-	float dx = 2.0f*(aspectratio*bcam->shift.x + bcam->offset.x*xaspect*2.0f);
-	float dy = 2.0f*(aspectratio*bcam->shift.y + bcam->offset.y*yaspect*2.0f);
-
-	cam->left += dx;
-	cam->right += dx;
-	cam->bottom += dy;
-	cam->top += dy;
+	if(bcam->type == CAMERA_ENVIRONMENT) {
+		/* set viewplane */
+		cam->left = 0.0f;
+		cam->right = 1.0f;
+		cam->bottom = 0.0f;
+		cam->top = 1.0f;
+	}
+	else {
+		/* set viewplane */
+		cam->left = -xaspect;
+		cam->right = xaspect;
+		cam->bottom = -yaspect;
+		cam->top = yaspect;
+
+		/* zoom for 3d camera view */
+		cam->left *= bcam->zoom;
+		cam->right *= bcam->zoom;
+		cam->bottom *= bcam->zoom;
+		cam->top *= bcam->zoom;
+
+		/* modify viewplane with camera shift and 3d camera view offset */
+		float dx = 2.0f*(aspectratio*bcam->shift.x + bcam->offset.x*xaspect*2.0f);
+		float dy = 2.0f*(aspectratio*bcam->shift.y + bcam->offset.y*yaspect*2.0f);
+
+		cam->left += dx;
+		cam->right += dx;
+		cam->bottom += dy;
+		cam->top += dy;
+	}
 
 	/* clipping distances */
 	cam->nearclip = bcam->nearclip;
 	cam->farclip = bcam->farclip;
 
-	/* orthographic */
-	cam->ortho = bcam->ortho;
+	/* type */
+	cam->type = bcam->type;
 
 	/* perspective */
 	cam->fov = 2.0f*atan((0.5f*sensor_size)/bcam->lens/aspectratio);
@@ -200,8 +212,24 @@ static void blender_camera_sync(Camera *cam, BlenderCamera *bcam, int width, int
 	cam->blades = bcam->apertureblades;
 	cam->bladesrotation = bcam->aperturerotation;
 
-	/* transform, note the blender camera points along the negative z-axis */
-	cam->matrix = bcam->matrix * transform_scale(1.0f, 1.0f, -1.0f);
+	/* transform */
+	cam->matrix = bcam->matrix;
+
+	if(bcam->type == CAMERA_ENVIRONMENT) {
+		/* make it so environment camera needs to be pointed in the direction
+		   of the positive x-axis to match an environment texture, this way
+		   it is looking at the center of the texture */
+		cam->matrix = cam->matrix *
+			make_transform( 0.0f, -1.0f, 0.0f, 0.0f,
+			                0.0f,  0.0f, 1.0f, 0.0f,
+			               -1.0f,  0.0f, 0.0f, 0.0f,
+			                0.0f,  0.0f, 0.0f, 1.0f);
+	}
+	else {
+		/* note the blender camera points along the negative z-axis */
+		cam->matrix = cam->matrix * transform_scale(1.0f, 1.0f, -1.0f);
+	}
+
 	cam->matrix = transform_clear_scale(cam->matrix);
 
 	/* set update flag */
@@ -269,7 +297,7 @@ void BlenderSync::sync_view(BL::SpaceView3D b_v3d, BL::RegionView3D b_rv3d, int
 		bcam.farclip *= 0.5;
 		bcam.nearclip = -bcam.farclip;
 
-		bcam.ortho = true;
+		bcam.type = CAMERA_ORTHOGRAPHIC;
 		bcam.ortho_scale = b_rv3d.view_distance();
 	}
 
diff --git a/intern/cycles/kernel/kernel_camera.h b/intern/cycles/kernel/kernel_camera.h
index 2dbdd076891..251b2c280da 100644
--- a/intern/cycles/kernel/kernel_camera.h
+++ b/intern/cycles/kernel/kernel_camera.h
@@ -122,6 +122,44 @@ __device void camera_sample_orthographic(KernelGlobals *kg, float raster_x, floa
 #endif
 }
 
+/* Environment Camera */
+
+__device void camera_sample_environment(KernelGlobals *kg, float raster_x, float raster_y, Ray *ray)
+{
+	Transform rastertocamera = kernel_data.cam.rastertocamera;
+	float3 Pcamera = transform(&rastertocamera, make_float3(raster_x, raster_y, 0.0f));
+
+	/* create ray form raster position */
+	ray->P = make_float3(0.0, 0.0f, 0.0f);
+	ray->D = equirectangular_to_direction(Pcamera.x, Pcamera.y);
+
+	/* transform ray from camera to world */
+	Transform cameratoworld = kernel_data.cam.cameratoworld;
+
+	ray->P = transform(&cameratoworld, ray->P);
+	ray->D = transform_direction(&cameratoworld, ray->D);
+	ray->D = normalize(ray->D);
+
+#ifdef __RAY_DIFFERENTIALS__
+	/* ray differential */
+	ray->dP.dx = make_float3(0.0f, 0.0f, 0.0f);
+	ray->dP.dy = make_float3(0.0f, 0.0f, 0.0f);
+
+	Pcamera = transform(&rastertocamera, make_float3(raster_x + 1.0f, raster_y, 0.0f));
+	ray->dD.dx = equirectangular_to_direction(Pcamera.x, Pcamera.y) - ray->D;
+
+	Pcamera = transform(&rastertocamera, make_float3(raster_x, raster_y + 1.0f, 0.0f));
+	ray->dD.dy = equirectangular_to_direction(Pcamera.x, Pcamera.y) - ray->D;
+#endif
+
+#ifdef __CAMERA_CLIPPING__
+	/* clipping */
+	ray->t = kernel_data.cam.cliplength;
+#else
+	ray->t = FLT_MAX;
+#endif
+}
+
 /* Common */
 
 __device void camera_sample(KernelGlobals *kg, int x, int y, float filter_u, float filter_v, float lens_u, float lens_v, Ray *ray)
@@ -134,10 +172,12 @@ __device void camera_sample(KernelGlobals *kg, int x, int y, float filter_u, flo
 	//ray->time = lerp(time_t, kernel_data.cam.shutter_open, kernel_data.cam.shutter_close);
 
 	/* sample */
-	if(kernel_data.cam.ortho)
+	if(kernel_data.cam.type == CAMERA_PERSPECTIVE)
+		camera_sample_perspective(kg, raster_x, raster_y, lens_u, lens_v, ray);
+	else if(kernel_data.cam.type == CAMERA_ORTHOGRAPHIC)
 		camera_sample_orthographic(kg, raster_x, raster_y, ray);
 	else
-		camera_sample_perspective(kg, raster_x, raster_y, lens_u, lens_v, ray);
+		camera_sample_environment(kg, raster_x, raster_y, ray);
 }
 
 CCL_NAMESPACE_END
diff --git a/intern/cycles/kernel/kernel_displace.h b/intern/cycles/kernel/kernel_displace.h
index 73666892cf3..f4b33605f5b 100644
--- a/intern/cycles/kernel/kernel_displace.h
+++ b/intern/cycles/kernel/kernel_displace.h
@@ -41,9 +41,11 @@ __device void kernel_shader_evaluate(KernelGlobals *kg, uint4 *input, float4 *ou
 	else { // SHADER_EVAL_BACKGROUND
 		/* setup ray */
 		Ray ray;
+		float u = __int_as_float(in.x);
+		float v = __int_as_float(in.y);
 
 		ray.P = make_float3(0.0f, 0.0f, 0.0f);
-		ray.D = make_float3(__int_as_float(in.x), __int_as_float(in.y), __int_as_float(in.z));
+		ray.D = equirectangular_to_direction(u, v);
 		ray.t = 0.0f;
 
 #ifdef __RAY_DIFFERENTIALS__
diff --git a/intern/cycles/kernel/kernel_light.h b/intern/cycles/kernel/kernel_light.h
index aa125180a94..42260577069 100644
--- a/intern/cycles/kernel/kernel_light.h
+++ b/intern/cycles/kernel/kernel_light.h
@@ -120,13 +120,9 @@ __device float3 background_light_sample(KernelGlobals *kg, float randu, float ra
 	float du = (randu - cdf_u.y) / (cdf_next_u.y - cdf_u.y);
 	float u = (index_u + du) / res;
 
-	/* spherical coordinates */
-	float theta = v * M_PI_F;
-	float phi = u * M_PI_F * 2.0f;
-
 	/* compute pdf */
 	float denom = cdf_last_u.x * cdf_last_v.x;
-	float sin_theta = sinf(theta);
+	float sin_theta = sinf(M_PI_F * v);
 
 	if(sin_theta == 0.0f || denom == 0.0f)
 		*pdf = 0.0f;
@@ -136,7 +132,7 @@ __device float3 background_light_sample(KernelGlobals *kg, float randu, float ra
 	*pdf *= kernel_data.integrator.pdf_lights;
 
 	/* compute direction */
-	return spherical_to_direction(theta, phi);
+	return -equirectangular_to_direction(u, v);
 }
 
 __device float background_light_pdf(KernelGlobals *kg, float3 direction)
diff --git a/intern/cycles/kernel/kernel_montecarlo.h b/intern/cycles/kernel/kernel_montecarlo.h
index 9776baf65e4..66bd0ee9998 100644
--- a/intern/cycles/kernel/kernel_montecarlo.h
+++ b/intern/cycles/kernel/kernel_montecarlo.h
@@ -185,7 +185,7 @@ __device float2 regular_polygon_sample(float corners, float rotation, float u, f
 	return make_float2(cr*p.x - sr*p.y, sr*p.x + cr*p.y);
 }
 
-/* Spherical coordinates <-> Cartesion direction  */
+/* Spherical coordinates <-> Cartesian direction  */
 
 __device float2 direction_to_spherical(float3 dir)
 {
@@ -203,11 +203,11 @@ __device float3 spherical_to_direction(float theta, float phi)
 		cosf(theta));
 }
 
-/* Equirectangular */
+/* Equirectangular coordinates <-> Cartesian direction */
 
 __device float2 direction_to_equirectangular(float3 dir)
 {
-	float u = (atan2f(dir.y, dir.x) + M_PI_F)/(2.0f*M_PI_F);
+	float u = -atan2f(dir.y, dir.x)/(2.0f*M_PI_F) + 0.5f;
 	float v = atan2f(dir.z, hypotf(dir.x, dir.y))/M_PI_F + 0.5f;
 
 	return make_float2(u, v);
@@ -215,9 +215,8 @@ __device float2 direction_to_equirectangular(float3 dir)
 
 __device float3 equirectangular_to_direction(float u, float v)
 {
-	/* XXX check correctness? */
-	float theta = M_PI_F*v;
-	float phi = 2.0f*M_PI_F*u;
+	float phi = M_PI_F*(1.0f - 2.0f*u);
+	float theta = M_PI_F*(1.0f - v);
 
 	return make_float3(
 		sin(theta)*cos(phi),
diff --git a/intern/cycles/kernel/kernel_types.h b/intern/cycles/kernel/kernel_types.h
index 9f4d5b00e2c..61335d5f9fa 100644
--- a/intern/cycles/kernel/kernel_types.h
+++ b/intern/cycles/kernel/kernel_types.h
@@ -240,6 +240,14 @@ typedef enum LightType {
 	LIGHT_AREA
 } LightType;
 
+/* Camera Type */
+
+enum CameraType {
+	CAMERA_PERSPECTIVE,
+	CAMERA_ORTHOGRAPHIC,
+	CAMERA_ENVIRONMENT
+};
+
 /* Differential */
 
 typedef struct differential3 {
@@ -387,7 +395,7 @@ typedef struct ShaderData {
 
 typedef struct KernelCamera {
 	/* type */
-	int ortho;
+	int type;
 	int pad1, pad2, pad3;
 
 	/* matrices */
diff --git a/intern/cycles/render/camera.cpp b/intern/cycles/render/camera.cpp
index a83ae81844c..6edf9c66f1d 100644
--- a/intern/cycles/render/camera.cpp
+++ b/intern/cycles/render/camera.cpp
@@ -35,7 +35,7 @@ Camera::Camera()
 
 	matrix = transform_identity();
 
-	ortho = false;
+	type = CAMERA_PERSPECTIVE;
 	fov = M_PI_F/4.0f;
 
 	nearclip = 1e-5f;
@@ -77,17 +77,21 @@ void Camera::update()
 	Transform ndctoraster = transform_scale(width, height, 1.0f);
 
 	/* raster to screen */
-	Transform screentoraster = ndctoraster *
+	Transform screentoraster = ndctoraster;
+	
+	screentoraster = ndctoraster *
 		transform_scale(1.0f/(right - left), 1.0f/(top - bottom), 1.0f) *
 		transform_translate(-left, -bottom, 0.0f);
 
 	Transform rastertoscreen = transform_inverse(screentoraster);
 
 	/* screen to camera */
-	if(ortho)
+	if(type == CAMERA_PERSPECTIVE)
+		screentocamera = transform_inverse(transform_perspective(fov, nearclip, farclip));
+	else if(type == CAMERA_ORTHOGRAPHIC)
 		screentocamera = transform_inverse(transform_orthographic(nearclip, farclip));
 	else
-		screentocamera = transform_inverse(transform_perspective(fov, nearclip, farclip));
+		screentocamera = transform_identity();
 
 	rastertocamera = screentocamera * rastertoscreen;
 
@@ -98,16 +102,20 @@ void Camera::update()
 	worldtoraster = transform_inverse(rastertoworld);
 
 	/* differentials */
-	if(ortho) {
+	if(type == CAMERA_ORTHOGRAPHIC) {
 		dx = transform_direction(&rastertocamera, make_float3(1, 0, 0));
 		dy = transform_direction(&rastertocamera, make_float3(0, 1, 0));
 	}
-	else {
+	else if(type == CAMERA_PERSPECTIVE) {
 		dx = transform(&rastertocamera, make_float3(1, 0, 0)) -
 		     transform(&rastertocamera, make_float3(0, 0, 0));
 		dy = transform(&rastertocamera, make_float3(0, 1, 0)) -
 		     transform(&rastertocamera, make_float3(0, 0, 0));
 	}
+	else {
+		dx = make_float3(0, 0, 0);
+		dy = make_float3(0, 0, 0);
+	}
 
 	dx = transform_direction(&cameratoworld, dx);
 	dy = transform_direction(&cameratoworld, dy);
@@ -147,7 +155,7 @@ void Camera::device_update(Device *device, DeviceScene *dscene)
 	kcam->shutterclose = shutterclose;
 
 	/* type */
-	kcam->ortho = ortho;
+	kcam->type = type;
 
 	/* store differentials */
 	kcam->dx = float3_to_float4(dx);
@@ -173,7 +181,7 @@ bool Camera::modified(const Camera& cam)
 		(blades == cam.blades) &&
 		(bladesrotation == cam.bladesrotation) &&
 		(focaldistance == cam.focaldistance) &&
-		(ortho == cam.ortho) &&
+		(type == cam.type) &&
 		(fov == cam.fov) &&
 		(nearclip == cam.nearclip) &&
 		(farclip == cam.farclip) &&
diff --git a/intern/cycles/render/camera.h b/intern/cycles/render/camera.h
index 43537ce8c3c..cfcc5406ee3 100644
--- a/intern/cycles/render/camera.h
+++ b/intern/cycles/render/camera.h
@@ -19,6 +19,8 @@
 #ifndef __CAMERA_H__
 #define __CAMERA_H__
 
+#include "kernel_types.h"
+
 #include "util_transform.h"
 #include "util_types.h"
 
@@ -44,8 +46,8 @@ public:
 	uint blades;
 	float bladesrotation;
 
-	/* orthographic/perspective */
-	bool ortho;
+	/* type */
+	CameraType type;
 	float fov;
 
 	/* clipping */
diff --git a/intern/cycles/render/light.cpp b/intern/cycles/render/light.cpp
index 405aa800457..bd3acb00f6d 100644
--- a/intern/cycles/render/light.cpp
+++ b/intern/cycles/render/light.cpp
@@ -45,9 +45,8 @@ static void dump_background_pixels(Device *device, DeviceScene *dscene, int res,
 		for(int x = 0; x < width; x++) {
 			float u = x/(float)width;
 			float v = y/(float)height;
-			float3 D = -equirectangular_to_direction(u, v);
 
-			uint4 in = make_uint4(__float_as_int(D.x), __float_as_int(D.y), __float_as_int(D.z), 0);
+			uint4 in = make_uint4(__float_as_int(u), __float_as_int(v), 0, 0);
 			d_input_data[x + y*width] = in;
 		}
 	}