Assn 3 - Basic Shading

All code for this assignment can be found here

PHONG Screenshot:

Coordinate System Used RHS Camera Location (0, 1, 7) looking at origin with (0, 1, 0) as up vector Blue Sphere Radius 1.3 Units Blue Sphere Position (2.3, -0.3, 2.2) Blue Sphere Illumination Model Phong (k_a = 0.9, k_d = 0.3, k_s = 0.65, k_e = 50) Red Sphere Radius 1 Unit Red Sphere Position (0.1, 1, 4.5) Red Sphere Illumination Model Phong (k_a = 0.9, k_d = 0.3, k_s = 0.65, k_e = 50) Floor Size 10x70 Floor Position (TL, TR, BL, BR) (-3, -1.5, -60), (7, -1.5, -60), (-3, -1.5, 10), (7, -1.5, 10) Floor Illumination Model Phong (k_a = 0.9, k_d = 0.3, k_s = 0.65, k_e = 50) Image WidthxHeight (pixels) 512x368 Focal Length 0.5 Units Film Plane WidthxHeight (Units) 1.33x1.0

PHONG (with SUPERSAMPLING) Screenshot:

Coordinate System Used RHS Camera Location (0, 1, 7) looking at origin with (0, 1, 0) as up vector Blue Sphere Radius 1.3 Units Blue Sphere Position (2.3, -0.3, 2.2) Blue Sphere Illumination Model Phong (k_a = 0.9, k_d = 0.3, k_s = 0.65, k_e = 50) Red Sphere Radius 1 Unit Red Sphere Position (0.1, 1, 4.5) Red Sphere Illumination Model Phong (k_a = 0.9, k_d = 0.3, k_s = 0.65, k_e = 50) Floor Size 10x70 Floor Position (TL, TR, BL, BR) (-3, -1.5, -60), (7, -1.5, -60), (-3, -1.5, 10), (7, -1.5, 10) Floor Illumination Model Phong (k_a = 0.9, k_d = 0.3, k_s = 0.65, k_e = 50) Image WidthxHeight (pixels) 512x368 Focal Length 0.5 Units Film Plane WidthxHeight (Units) 1.33x1.0

Selected differences between phong with/without supersampling

PHONG-BLINN (with SUPERSAMPLING) Screenshot:

Coordinate System Used RHS Camera Location (0, 1, 7) looking at origin with (0, 1, 0) as up vector Blue Sphere Radius 1.3 Units Blue Sphere Position (2.3, -0.3, 2.2) Blue Sphere Illumination Model Phong-Blinn (k_a = 0.9, k_d = 0.3, k_s = 0.65, k_e = 50) Red Sphere Radius 1 Unit Red Sphere Position (0.1, 1, 4.5) Red Sphere Illumination Model Phong-Blinn (k_a = 0.9, k_d = 0.3, k_s = 0.65, k_e = 50) Floor Size 10x70 Floor Position (TL, TR, BL, BR) (-3, -1.5, -60), (7, -1.5, -60), (-3, -1.5, 10), (7, -1.5, 10) Floor Illumination Model Phong (k_a = 0.9, k_d = 0.3, k_s = 0.65, k_e = 50) Image WidthxHeight (pixels) 512x368 Focal Length 0.5 Units Film Plane WidthxHeight (Units) 1.33x1.0

ASHIKHMIN-SHIRLEY (no mods) (with SUPERSAMPLING) Screenshot 1:

Coordinate System Used RHS Camera Location (0, 1, 7) looking at origin with (0, 1, 0) as up vector Blue Sphere Radius 1.3 Units Blue Sphere Position (2.3, -0.3, 2.2) Blue Sphere Illumination Model Ashikhmin-Shirley (n_u = 10, n_v = 1000, r_s = 0.1, r_d = 0.9) Red Sphere Radius 1 Unit Red Sphere Position (0.1, 1, 4.5) Red Sphere Illumination Model Ashikhmin-Shirley (n_u = 10, n_v = 1000, r_s = 0.1, r_d = 0.9) Floor Size 10x70 Floor Position (TL, TR, BL, BR) (-3, -1.5, -60), (7, -1.5, -60), (-3, -1.5, 10), (7, -1.5, 10) Floor Illumination Model Phong (k_a = 0.9, k_d = 0.3, k_s = 0.65, k_e = 50) Image WidthxHeight (pixels) 512x368 Focal Length 0.5 Units Film Plane WidthxHeight (Units) 1.33x1.0

The following mods were used to create a brighter image:

When calculating the final Radiance, I also added 0.2 * object_color * background_radiance for each of the RGB bands

The regular diffuse calculation has a factor of (1 - R_s). When R_s is high enough, this can vastly reduce the diffuse component. To counter this, I have changed it to (1 - 0.5 * R_s), resulting in a brighter image even for high values of R_s.

ASHIKHMIN-SHIRLEY (with mods) (with SUPERSAMPLING) Screenshot 2:

Coordinate System Used RHS Camera Location (0, 1, 7) looking at origin with (0, 1, 0) as up vector Blue Sphere Radius 1.3 Units Blue Sphere Position (2.3, -0.3, 2.2) Blue Sphere Illumination Model Ashikhmin-Shirley (n_u = 1000, n_v = 10, r_s = 0.1, r_d = 0.9) Red Sphere Radius 1 Unit Red Sphere Position (0.1, 1, 4.5) Red Sphere Illumination Model Ashikhmin-Shirley (n_u = 1000, n_v = 10, r_s = 0.1, r_d = 0.9) Floor Size 10x70 Floor Position (TL, TR, BL, BR) (-3, -1.5, -60), (7, -1.5, -60), (-3, -1.5, 10), (7, -1.5, 10) Floor Illumination Model Phong (k_a = 0.9, k_d = 0.3, k_s = 0.65, k_e = 50) Image WidthxHeight (pixels) 512x368 Focal Length 0.5 Units Film Plane WidthxHeight (Units) 1.33x1.0

ASHIKHMIN-SHIRLEY (with mods) (with SUPERSAMPLING) Screenshot 3:

Coordinate System Used RHS Camera Location (0, 1, 7) looking at origin with (0, 1, 0) as up vector Blue Sphere Radius 1.3 Units Blue Sphere Position (2.3, -0.3, 2.2) Blue Sphere Illumination Model Ashikhmin-Shirley (n_u = 100, n_v = 100, r_s = 0.1, r_d = 0.9) Red Sphere Radius 1 Unit Red Sphere Position (0.1, 1, 4.5) Red Sphere Illumination Model Ashikhmin-Shirley (n_u = 100, n_v = 100, r_s = 0.1, r_d = 0.9) Floor Size 10x70 Floor Position (TL, TR, BL, BR) (-3, -1.5, -60), (7, -1.5, -60), (-3, -1.5, 10), (7, -1.5, 10) Floor Illumination Model Phong (k_a = 0.9, k_d = 0.3, k_s = 0.65, k_e = 50) Image WidthxHeight (pixels) 512x368 Focal Length 0.5 Units Film Plane WidthxHeight (Units) 1.33x1.0