Shure,
up left corner + -> Configure Viewports -> Layout
Pick the desired viewport and select ActiveShade from the menu
Greetings
Paulo Alves Pereira
It is not exactly a mirror as it doesn't mirror other display as the external window of activeshade does, you choose the view and once choosen as activeshade you can not change it. Another thing is that if you save and load the project the activeshade view can change to something else forcing you to re configure the displays
Thank you both for answering. I wanted to update my question, but Area won't allow it.
I want to use 3 out of the 4 viewports normally, I want the 4th, the active shade, to reflect the current viewport I'm using as well as any changes I make.
I'm pretty sure Max does not support this natively, like KarlAkimorsaid, but since Corona does and it's an awesome thing to have- I just wanted to make sure that Max can't do it atm, and then suggest that it should be able to do it asap.
Here is the video of what I originally meant: https://youtu.be/uewtBJuONe0?t=1m47s
Well, if the activeview is in a camera and if you choose the same camera in another view then any change of the camera in that view will mirror the changes in the activeview. Then, yes, you will have something that will look identical to your video. But it is not a mirror of the view but of the camera and only can be a camera. This makes sense when you compare it with the external window activeview that will mirror any view of Max or will change between cameras or views, something that the integrated version can not do. In order to change the camera to another camera or view you need to leave active shade, change the view and then enter in activeshade again.