Fisheye Camera for Cycles

For sample images see:
http://www.dalaifelinto.com/?p=399 (equisolid)
http://www.dalaifelinto.com/?p=389 (equidistant)

The 'use_panorama' option is now part of a new Camera type: 'Panorama'.
Created two other panorama cameras:

- Equisolid: most of lens in the market simulate this lens - e.g. Nikon, Canon, ...)
             this works as a real lens up to an extent. The final result takes the
             sensor dimensions into account also.
             .:. to simulate a Nikon DX2S with a 10.5mm lens do:
                 sensor: 23.7 x 15.7
                 fisheye lens: 10.5
                 fisheye fov: 180
                 render dimensions: 4288 x 2848

- Equidistant: this is not a real lens model. Although the old equidistant lens simulate
               this lens. The result is always as a circular fisheye that takes the whole sensor
               (in other words, it doesn't take the sensor into consideration).
               This is perfect for fulldomes ;)

               For the UI we have 10 to 360 as soft values and 10 to 3600 as hard values (because we can).


Reference material:
http://www.hdrlabs.com/tutorials/downloads_files/HDRI%20for%20CGI.pdf
http://www.bobatkins.com/photography/technical/field_of_view.html

Note, this is not a real simulation of the light path through the lens.
The ideal solution would be this:
https://graphics.stanford.edu/wikis/cs348b-11/Assignment3
http://www.graphics.stanford.edu/papers/camera/


Thanks Brecht for the fix, suggestions and code review.
Kudos for the dome community for keeping me stimulated on the topic since 2009 ;)

Patch partly implemented during lab time at VisGraf, IMPA - Rio de Janeiro.

3 files changed, 70 insertions, 5 deletions

diff --git a/intern/cycles/blender/addon/enums.py b/intern/cycles/blender/addon/enums.py
index b4b1646c10d..6cc3010eb0e 100644
--- a/intern/cycles/blender/addon/enums.py
+++ b/intern/cycles/blender/addon/enums.py
@@ -54,3 +54,9 @@ aperture_types = (
     ('RADIUS', "Radius", "Directly change the size of the aperture"),
     ('FSTOP', "F/stop", "Change the size of the aperture by f/stops"),
     )
+
+panorama_types = (
+    ('EQUIRECTANGULAR', "Equirectangular", "Render the scene with a spherical camera, also known as Lat Long panorama"),
+    ('FISHEYE_EQUIDISTANT', "Fisheye Equidistant", "Ideal for fulldomes, ignore the sensor dimensions"),
+    ('FISHEYE_EQUISOLID', "Fisheye Equisolid", "Similar to most fisheye modern lens, take sensor dimensions into consideration"),
+    )
diff --git a/intern/cycles/blender/addon/properties.py b/intern/cycles/blender/addon/properties.py
index 35f97bf629f..fb066a3a939 100644
--- a/intern/cycles/blender/addon/properties.py
+++ b/intern/cycles/blender/addon/properties.py
@@ -278,6 +278,25 @@ class CyclesCameraSettings(bpy.types.PropertyGroup):
                 subtype='ANGLE',
                 default=0,
                 )
+        cls.panorama_type = EnumProperty(
+                name="Panorama Type",
+                description="Distortion to use for the calculation",
+                items=enums.panorama_types,
+                default='FISHEYE_EQUISOLID',
+                )
+        cls.fisheye_fov = FloatProperty(
+                name="Field of View",
+                description="Field of view for the fisheye lens",
+                min=0.1745, soft_max=2*math.pi, max=10.0*math.pi,
+                subtype='ANGLE',
+                default=math.pi,
+                )
+        cls.fisheye_lens = FloatProperty(
+                name="Fisheye Lens",
+                description="Lens focal length (mm))",
+                min=0.01, soft_max=15.0, max=100.0,
+                default=10.5,
+                )
 
     @classmethod
     def unregister(cls):
diff --git a/intern/cycles/blender/blender_camera.cpp b/intern/cycles/blender/blender_camera.cpp
index 55a32d8fc10..bdd02bb5086 100644
--- a/intern/cycles/blender/blender_camera.cpp
+++ b/intern/cycles/blender/blender_camera.cpp
@@ -48,6 +48,10 @@ struct BlenderCamera {
 
 	float2 pixelaspect;
 
+	PanoramaType panorama_type;
+	float fisheye_fov;
+	float fisheye_lens;
+
 	enum { AUTO, HORIZONTAL, VERTICAL } sensor_fit;
 	float sensor_width;
 	float sensor_height;
@@ -94,9 +98,37 @@ 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->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;
+		switch(b_camera.type())
+		{
+			case BL::Camera::type_ORTHO:
+				bcam->type = CAMERA_ORTHOGRAPHIC;
+				break;
+			case BL::Camera::type_PANO:
+				bcam->type = CAMERA_PANORAMA;
+				break;
+			case BL::Camera::type_PERSP:
+			default:
+				bcam->type = CAMERA_PERSPECTIVE;
+				break;
+		}	
+
+		switch(RNA_enum_get(&ccamera, "panorama_type"))
+		{
+			case 1:
+				bcam->panorama_type = PANORAMA_FISHEYE_EQUIDISTANT;
+				break;
+			case 2:
+				bcam->panorama_type = PANORAMA_FISHEYE_EQUISOLID;
+				break;
+			case 0:
+			default:
+				bcam->panorama_type = PANORAMA_EQUIRECTANGULAR;
+				break;
+		}	
+
+		bcam->fisheye_fov = RNA_float_get(&ccamera, "fisheye_fov");
+		bcam->fisheye_lens = RNA_float_get(&ccamera, "fisheye_lens");
+
 		bcam->ortho_scale = b_camera.ortho_scale();
 
 		bcam->lens = b_camera.lens();
@@ -138,7 +170,7 @@ static Transform blender_camera_matrix(const Transform& tfm, CameraType type)
 {
 	Transform result;
 
-	if(type == CAMERA_ENVIRONMENT) {
+	if(type == CAMERA_PANORAMA) {
 		/* 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 */
@@ -172,6 +204,9 @@ static void blender_camera_sync(Camera *cam, BlenderCamera *bcam, int width, int
 	bool horizontal_fit;
 	float sensor_size;
 
+	cam->sensorwidth = bcam->sensor_width;
+	cam->sensorheight = bcam->sensor_height;
+
 	if(bcam->sensor_fit == BlenderCamera::AUTO) {
 		horizontal_fit = (xratio > yratio);
 		sensor_size = bcam->sensor_width;
@@ -203,7 +238,7 @@ static void blender_camera_sync(Camera *cam, BlenderCamera *bcam, int width, int
 		aspectratio = bcam->ortho_scale/2.0f;
 	}
 
-	if(bcam->type == CAMERA_ENVIRONMENT) {
+	if(bcam->type == CAMERA_PANORAMA) {
 		/* set viewplane */
 		cam->left = 0.0f;
 		cam->right = 1.0f;
@@ -240,6 +275,11 @@ static void blender_camera_sync(Camera *cam, BlenderCamera *bcam, int width, int
 	/* type */
 	cam->type = bcam->type;
 
+	/* panorama */
+	cam->panorama_type = bcam->panorama_type;
+	cam->fisheye_fov = bcam->fisheye_fov;
+	cam->fisheye_lens = bcam->fisheye_lens;
+
 	/* perspective */
 	cam->fov = 2.0f*atan((0.5f*sensor_size)/bcam->lens/aspectratio);
 	cam->focaldistance = bcam->focaldistance;