Look up and down

Description

Our camera heading lets us look around horizontally (i.e. left and right). To look around vertically, we'll need to capture another angle.

This change introduces the camera pitch which captures the vertical angle (i.e. up and down). The functionality is similar to the camera heading, but we're using a different rotational matrix to spin the camera around the X axis. We're also using the conventions outlined here to define pitch:

Note that we're not including pitch in our velocity. Even if you're looking down or up, you'll still move parallel to the X-Z plane. This is how we'll likely implement it when we support walking on the world, so leaving it as-is for now.

Note that we are clamping the pitch between straight up (PI/2) and straight down (-PI/2). If you exceed those values you would flip the world upside down, which can be very disorienting.

Screenshot

Commands

git clone git@github.com:atsheehan/iridium
cd iridium
git checkout 1b3134f16dd5e9804ee95e1aa2b4626c9adea5d5
cargo run --release

Code Changes

Modified shaders/cube.vertGitHub

@@ -5,6 +5,7 @@
55  

66  uniform vec3 camera_position;

77  uniform float camera_heading;

8+ uniform float camera_pitch;

89  uniform vec3 position;

910  uniform float aspect_ratio = 1.0;

1011  

@@ -96,7 +97,15 @@
9697           sin(camera_heading), 0.0, cos(camera_heading), 0.0,

9798           0.0, 0.0, 0.0, 1.0);

9899  

99-   mat4 world_to_camera_transform = camera_translation * camera_heading_rotation;

100+   mat4 camera_pitch_rotation =

101+     mat4(1.0, 0.0, 0.0, 0.0,

102+          0.0, cos(camera_pitch), sin(camera_pitch), 0.0,

103+          0.0, -sin(camera_pitch), cos(camera_pitch), 0.0,

104+          0.0, 0.0, 0.0, 1.0);

105+ 

106+   mat4 world_to_camera_transform = camera_translation *

107+     camera_heading_rotation *

108+     camera_pitch_rotation;

100109  

101110    mat4 camera_to_clip_transform =

102111      mat4(1.0, 0.0, 0.0, 0.0,

@@ -5,6 +5,7 @@
5  

6  uniform vec3 camera_position;

7  uniform float camera_heading;

 
8  uniform vec3 position;

9  uniform float aspect_ratio = 1.0;

10  

@@ -96,7 +97,15 @@
96           sin(camera_heading), 0.0, cos(camera_heading), 0.0,

97           0.0, 0.0, 0.0, 1.0);

98  

99-   mat4 world_to_camera_transform = camera_translation * camera_heading_rotation;

 
 
 
 
 
 
 
 
100  

101    mat4 camera_to_clip_transform =

102      mat4(1.0, 0.0, 0.0, 0.0,

@@ -5,6 +5,7 @@
5  

6  uniform vec3 camera_position;

7  uniform float camera_heading;

8+ uniform float camera_pitch;

9  uniform vec3 position;

10  uniform float aspect_ratio = 1.0;

11  

@@ -96,7 +97,15 @@
97           sin(camera_heading), 0.0, cos(camera_heading), 0.0,

98           0.0, 0.0, 0.0, 1.0);

99  

100+   mat4 camera_pitch_rotation =

101+     mat4(1.0, 0.0, 0.0, 0.0,

102+          0.0, cos(camera_pitch), sin(camera_pitch), 0.0,

103+          0.0, -sin(camera_pitch), cos(camera_pitch), 0.0,

104+          0.0, 0.0, 0.0, 1.0);

105+ 

106+   mat4 world_to_camera_transform = camera_translation *

107+     camera_heading_rotation *

108+     camera_pitch_rotation;

109  

110    mat4 camera_to_clip_transform =

111      mat4(1.0, 0.0, 0.0, 0.0,

Modified src/render.rsGitHub

@@ -188,6 +188,8 @@
188188              .set_uniform_vec3("camera_position", camera.position());

189189          self.cube_program

190190              .set_uniform_f32("camera_heading", &camera.heading());

191+         self.cube_program

192+             .set_uniform_f32("camera_pitch", &camera.pitch());

191193      }

192194  }

193195  

@@ -188,6 +188,8 @@
188              .set_uniform_vec3("camera_position", camera.position());

189          self.cube_program

190              .set_uniform_f32("camera_heading", &camera.heading());

 
 
191      }

192  }

193  

@@ -188,6 +188,8 @@
188              .set_uniform_vec3("camera_position", camera.position());

189          self.cube_program

190              .set_uniform_f32("camera_heading", &camera.heading());

191+         self.cube_program

192+             .set_uniform_f32("camera_pitch", &camera.pitch());

193      }

194  }

195

Modified src/world.rsGitHub

@@ -15,6 +15,7 @@
1515              position: Vec3(0.0, 0.0, 0.0),

1616              velocity: Vec3(0.0, 0.0, 0.0),

1717              heading: 0.0,

18+             pitch: 0.0,

1819          };

1920  

2021          Self {

@@ -87,8 +88,13 @@
8788          self.camera.velocity = self.camera.velocity.set_y(0.0);

8889      }

8990  

90-     pub(crate) fn update_camera_direction(&mut self, dx: f32, _dy: f32) {

91+     pub(crate) fn update_camera_direction(&mut self, dx: f32, dy: f32) {

92+         const MIN_PITCH: f32 = -std::f32::consts::FRAC_PI_2;

93+         const MAX_PITCH: f32 = std::f32::consts::FRAC_PI_2;

94+ 

9195          self.camera.heading += dx * MOUSE_SENSITIVITY;

96+         self.camera.pitch =

97+             (self.camera.pitch + dy * MOUSE_SENSITIVITY).clamp(MIN_PITCH, MAX_PITCH);

9298      }

9399  

94100      pub(crate) fn camera(&self) -> &Camera {

@@ -100,6 +106,7 @@
100106      position: Vec3,

101107      velocity: Vec3,

102108      heading: f32,

109+     pitch: f32,

103110  }

104111  

105112  impl Camera {

@@ -110,4 +117,8 @@
110117      pub(crate) fn heading(&self) -> f32 {

111118          self.heading

112119      }

120+ 

121+     pub(crate) fn pitch(&self) -> f32 {

122+         self.pitch

123+     }

113124  }

@@ -15,6 +15,7 @@
15              position: Vec3(0.0, 0.0, 0.0),

16              velocity: Vec3(0.0, 0.0, 0.0),

17              heading: 0.0,

 
18          };

19  

20          Self {

@@ -87,8 +88,13 @@
87          self.camera.velocity = self.camera.velocity.set_y(0.0);

88      }

89  

90-     pub(crate) fn update_camera_direction(&mut self, dx: f32, _dy: f32) {

 
 
 
91          self.camera.heading += dx * MOUSE_SENSITIVITY;

 
 
92      }

93  

94      pub(crate) fn camera(&self) -> &Camera {

@@ -100,6 +106,7 @@
100      position: Vec3,

101      velocity: Vec3,

102      heading: f32,

 
103  }

104  

105  impl Camera {

@@ -110,4 +117,8 @@
110      pub(crate) fn heading(&self) -> f32 {

111          self.heading

112      }

 
 
 
 
113  }

@@ -15,6 +15,7 @@
15              position: Vec3(0.0, 0.0, 0.0),

16              velocity: Vec3(0.0, 0.0, 0.0),

17              heading: 0.0,

18+             pitch: 0.0,

19          };

20  

21          Self {

@@ -87,8 +88,13 @@
88          self.camera.velocity = self.camera.velocity.set_y(0.0);

89      }

90  

91+     pub(crate) fn update_camera_direction(&mut self, dx: f32, dy: f32) {

92+         const MIN_PITCH: f32 = -std::f32::consts::FRAC_PI_2;

93+         const MAX_PITCH: f32 = std::f32::consts::FRAC_PI_2;

94+ 

95          self.camera.heading += dx * MOUSE_SENSITIVITY;

96+         self.camera.pitch =

97+             (self.camera.pitch + dy * MOUSE_SENSITIVITY).clamp(MIN_PITCH, MAX_PITCH);

98      }

99  

100      pub(crate) fn camera(&self) -> &Camera {

@@ -100,6 +106,7 @@
106      position: Vec3,

107      velocity: Vec3,

108      heading: f32,

109+     pitch: f32,

110  }

111  

112  impl Camera {

@@ -110,4 +117,8 @@
117      pub(crate) fn heading(&self) -> f32 {

118          self.heading

119      }

120+ 

121+     pub(crate) fn pitch(&self) -> f32 {

122+         self.pitch

123+     }

124  }