Please don’t reply to five-year-old threads with random questions about why nobody replied.
For one, spamming old threads is actually against forum rules.
For two, “texture atlasing” is extremely well documented in the general sense, and given the context of the comment it replied to (combining meshes and minimizing drawcall batches for better performance), it’s pretty obvious that nobody here is going to retype the internet worth of knowledge around texture atlasing.
If you actually have an issue, please start your own new post. It’s FREE!
When you do, here is how to report your problem productively in the Unity3D forums:
How to understand compiler and other errors and even fix them yourself:
If you post a code snippet, ALWAYS USE CODE TAGS:
How to use code tags: https://discussions.unity.com/t/481379