Concerning phong shading and Gouraud shading in a $3\text{D}$ scene, which of the following statements are true?
- Gouraud shading requires more computation than phong shading
- Gouraud shading linearly interpolates the color of an interior pixel from the color at the vertices
- Phong shading interpolates over the normal vectors specified at the vertices
Choose the correct answer from the options given below:
- $(i)$ and $(ii)$ only
- $(i)$ and $(iii)$ only
- $(ii)$ and $(iii)$ only
- $(i), (ii)$ and $(iii)$
