Why is my retopologised mesh getting baked into my normal map?

I’m creating a low-poly mesh of an object but the final result seems to be quite ‘blocky’. When I take the object outside of Blender and place it in a 3D games editor the re-topolgised mesh is clearly visible, which makes me think I’m doing something wrong. Ideally the surface should look like a smooth plastic.

Here’s what I’m doing at the moment:

My process starts with baking a diffuse texture and normal map from a high quality mesh. I then apply these materials to a low-poly model (re-topologised externally from Blender)

I’ve noticed the retopologised mesh is very ‘blocky’. This is after smooth shader has been applied:

I then bake a normal map from a high-poly version which gives me the following results:

Below is an image of the normal map connected in Blender Cycles:

This is such an infuriating problem and as I’m new to Blender I have no idea where I’m going wrong! I’m using an online guide to carry out the baking process so if there isn’t enough information in this post, please refer to it here : https://sophiedixon.gitbooks.io/photogrammetry-guide/content/optimisation.html

Thank you!

I found a solution… The ‘blocky’ finish was caused by sharp edges in the retopologised mesh. In Edit Mode, select all, press CTRL + E and select Clear Sharp. That worked for me.