Tidy up

docs/lectures/graphics/07_camera.md

@@ -12,14 +12,14 @@ A camera involves
 3. A right direction
 4. An up direction
 
-Calculating a camera direction can be achieved using Euler angles, **pitch**, **yaw** and **roll** .
+Calculating a camera direction can be achieved using Euler angles, **pitch**, **yaw** and **roll**.
 
 - Pitch rotates the camera on the x axis
-  - Think of a plane pointing its nose to the floor or to the sky
+    - Think of a plane pointing its nose to the floor or to the sky
 - Yaw rotates the camera on the y axis
-  - Think a plane moving the nose left to right keeping the wings parallel with the ground
+    - Think of a plane moving the nose left to right keeping the wings parallel with the ground
 - Roll rotates the camera on the z axis
-  - Think tilting the plane’s wings left and right, but not changing the direction of the nose
+    - Think of tilting the plane’s wings left and right, but not changing the direction of the nose
 
 #### Model-Viewer Camera
 
@@ -49,7 +49,7 @@ The camera has a position in world space and a focus direction `front`, which ca
 
 We can move this kind of camera, forward, backward, left and right along with pitch, roll and yaw.
 
-The camera is at the center of the sphere, and the model moves around the edge of the sphere.
+The camera is at the centre of the sphere, and the model moves around the edge of the sphere.
 
 A unit vector points from the camera to the model as the front direction of the camera