Should we upload rest colors

[jw4149]

Dear Professor,
When firstly uploading the vertex attributes, should we upload the colors of the initial state along with positions and normals of the initial state ?
If so, how do we recalculate the colors later on the GPU side ? as it depends on normals, which changes according to translations and rotations.
Thank you.

[danielepanozzo]

If you want to specify different colors for the different objects yes, you should send an additional color attribute for each vertex. The shading of every fragment (which depends on the transformed normals and positions) should be computed in the fragments shader.

[jw4149]

Thank you professor. Another question, is using element buffer a must in this assignment ? Is it better to keep multiple copies of each vertex in the vertex array ?

[danielepanozzo]

No it is not required to use an element buffer in this assignment.