GLaDOS in PeTI level editor
You know what would be cool? If you could put GLaDOS in your PeTI map as an editor item! And, Wheatley in GLaDOS's body, too! I hope an update comes with this, or someone makes a mod for this! An option could be whether it was GLaDOS or Wheatley in GLaDOS's body, and, so you could choose whether voice lines and animations are enabled! SOMEONE PLEASE MAKE THIS MOD!
5/30/2017: OH LOOK I REMEMBERED I HAD THIS ACCOUNT
Try the FGEMOD, it has a "choreo" item that plays a GLaDOS line when triggered. At the moment I've only coded a few lines, but if you give me quotes I can add them in. Wheatley lines would be possible, but embedding the monitors in the walls is a bit annoying.
PeTI? Thats a funny way to spell hammer.
PortalStories.com
"Oh, in case you got covered in that repulsion gel, here's some advice the lab boys gave me: DO NOT get covered in the repulsion gel."
To be completely honest; I think this is too complex for a PTI mod. The PTI has always been designed to allow players to make basic puzzles. Nothing more, nothing less. The whole alternate universe stuff was there to fill up the lack of glados/wheatley lines. If you want to use more advanced things like voicelines, better visuals etc etc I highly recommend learning Hammer. You can do so much more with that.
To be completely honest; I think this is too complex for a PTI mod. The PTI has always been designed to allow players to make basic puzzles. Nothing more, nothing less. The whole alternate universe stuff was there to fill up the lack of glados/wheatley lines. If you want to use more advanced things like voicelines, better visuals etc etc I highly recommend learning Hammer. You can do so much more with that.
I have to agree with LP here. PTI is a puzzle maker, whereas Hammer is a level maker. I got into Hammer because I thought PTI wasn't enough, and I'm so glad that I did, because it's a much, much more powerful tool.
youwillnotregret.jpg
Why are people so afraid of hammer?
PortalStories.com
"Oh, in case you got covered in that repulsion gel, here's some advice the lab boys gave me: DO NOT get covered in the repulsion gel."
You have to admit that it looks mighty complicated when you open it for the first time. That's probably what scares people off. But while it needs a bit of commitment to learn, it's definitely no rocket science. Also, since the tools are so old, there are tons of tutorials for just about everything.
If I made it from this to this in about half a year, anyone can.
I guess it's quite intimidating at first. I remember the first time I ever tried to use Hammer, several years ago. The interface scared me and I had trouble creating the rectangular room outlined in the VDC tutorial 
All joking aside, that did happen.
I learned by editing PTI maps, and gradually working my way up. The "cross that bridge when you come to it" approach also helped, because I didn't have to learn everything at once. And now I consider myself a "fairly decent" mapper.
Whilst I agree that it's probably easy to start of with pti maps and editing it I think it's better practice to start completely from scratch. Pti instances are overly complicated to allow all the different possibilities the Pti allows. For example when I look at the elevator I almost get scares of the logic. It'd make me scared to make one. In hammer I only need to let the elevator move a certain distance, so a few props and a func_door are enough.
if you stick with the pti instances you'll keep running into the entity limit, resulting in game crashes if you're making big maps. Making your own stuff you'll be able to do much more. Also starting from scratch might make it easier to think outside the 128x128x128 blocks. Yes, it'll take time to get to know hammer but it'll be worth it. If you run into any problems, feel free to ask here 
What she said ^^^^
I love it when people drop these gems http://www.portal2sounds.com/154#q=all%20joking%20aside
indeed
I started in hammer because that was the only thing around when I started mapping, and I thought it was fun and (easy) to learn.
There are some great tutorials online which can teach you the basics, and this forum is a great resource of people who can always help you with whatever problem you might face with hammer