Save Snapshot is available in the Bookmarks menu (drop down next to star icon in viewport toolbar). It takes a snapshot with dimensions w x h (defined in dialog) where w matches the width of the viewport. The vertical amount of the viewport captured is determined by the specified aspect ratio. Snapshots can also be controlled in Python scripts.
Alternatively, you can export your scene and import it into other software that can produce high quality renderings.
I love that image!
Of course Cheryl is right on the mark. We used CityEngine on that image, but the final rendering was done in another program.
That is a fantastic image and is pretty representative of the work Houseal Lavigne does (I've long been a fan).
If you're looking to reduce the number of applications used, I've had a bit of success taking snapshots in CE and then configuring in Photoshop or GIMP. In CE you can ensure that the snapshot is in the same location and then blend different versions. The image below was two snapshots, with and without wireframes, and merged with transparency. I was going for something muted but you could do things to give it a more textured aesthetic.
LumenRT might be worth looking into if you have the funds. Unfortunately ever since its acquisition by Bentley, its price dectupled.
Also a small hint: the CE screenshot function isn't limited by your screen resolution, you can for example make 4k screenshots on a 1080p monitor.
Thanks for the input everyone. I apologize for not giving credit to Houseal Lavigne Associates for that original photo. They do amazing work and I have been trying learn from it ever since they participated in that SketchUp/CityEngine webinar.