[G3 Q&A, Help & Troubleshooting] Redline:
* I am not responsible for bricked devices, displays not working, or your phone melting *

Now with that out of the way, hello! Welcome to my first guide-thingy. As it is my first, I apologise if there is a mistake or if I have left something out, but this process is exactly the process I have used.

Recently I've had a few people ask me about changing their phone's resolution and DPI as said in my signature, so I thought I'd write up a guide for people to use! The ROM I've done this on is the BlissPop AOSP ROM but the process should be similar for most if not all other Custom AOSP-Based ROMs. I am UNSURE if this process works on the stock ROM or any stock-based ROMs.

Prerequisites:

- Root access

- Root File Manager & Explorer (Such as Root Browser or ES File Explorer)

* Root Browser: https://tinyurl.com/aytbttu

*ES File Explorer: https://tinyurl.com/cd4u27q

- NOMone Resolution Changer

* https://tinyurl.com/kjg63jn

- OPTIONAL (For Multi-DPI Patch) Latest AROMA (Now known as Open) GApps Package

* http://xdaforums.com/android/software/pa-gapps-continuation-t3098071

Lets get started!

Firstly, the Multi DPI Patch. It's not essential but allows apps to be properly resized to match your custom DPI, and in the latest Google Apps package it has an option when installing to install a multi-DPI patch for people who are using custom resolutions on their phone. Like me, I'm not using 2560x1440 (Stock 1440p resolution) I'm using 1920x1080 (1080p) resolution @ 370 DPI.

Changing your Resolution & DPI

1. Download NoMone Resolution Changer from the Play Store above (It's free) and grant root access

2a. Open a root file manager (Like Root Browser or ES File Explorer (You have to enable root-access for ES) ) and navigate to the /system folder on internal storage. Find your build.prop at the bottom. Now, you're going to want to create a backup of this file before we do anything as it defines how things work on the phone, so create a copy and move it somewhere safe from being wiped (Like an external SD card)

2b. Click on build.prop and open with a root file browser

2c. Find the line under the #ADDITIONAL_BUILD_PROPERTIES section that says ro.sf.lcd_density=xxx and change 560 (default DPI) to something like 430 if you want the font and stuff to stay the same size or 370 to make it smaller and hit save, grant root-save access if required. Then, open the file with another file manager to verify it's saved and changed. Adjust the DPI to something that you like, but be cautious as not all DPIs work properly (I only know of 370 & 430 that have worked for me). This step may vary depending on how your ROM sets out your build.prop.

3. Set your desired resolution in NOMone Resolution Changer (Mine is 1080x1920, remember to do it backwards so 1080x1920 not 1920x1080 otherwise your phone's GUI will be landscape and not portrait, and will go off the screen)

3b. Set your desired DPI to match the DPI you put into your build.prop file and hit apply (Grant root access if requested). The app will apply your settings and change your screen to match the new settings. It will then prompt you if you'd like to keep these settings, hit yes or no. If you hit yes, it will give you an option to change back the settings after a minute so you can see what the phone looks like at that setting.

*This next step only applies if your ROM has an option to manage the DPI setting itself, like BlissPop does, otherwise skip it*

4. After you've applied your custom resolution and DPI, go to Settings (Yes everything will be massive-sized don't worry) -> Display & Lights -> Scroll down to the bottom, hit advanced Display Settings, and change the LCD Density DPI to match the one you set in your build.prop and NOMone app.

5. Hit yes to reboot or reboot your phone if not prompted.

6. You're done! Your phone should reboot and apply your new resolution and DPI changes.

I have attached some screenshots showing off the BlissPop & Facebook UI at 1920x1080 Resolution & 370 DPI, as well as an example change in the NOMone Resolution Changer App. Lowering the Resolution and DPI is beneficial to those who want to squeeze more stuff onto their screen (it enables lots more text on the screen that isn't really big.) As well as gamers (The lower resolution doesn't strain the GPU as hard.)

If you have any issues, just delete the build.prop you edited from the /system folder in TWRP and copy over the original one you backed up and put it in the /system folder.

Known issues caused by this guide:

- Boot animation may stretch when booting.

- Recent app previews will also be larger for some unknown reason, this is a small side effect however.

Hope this helped!