Cubical / Spherical confusion

Hi all,

I'm (re)startting with Krpano tools and I'm still a bit confused about the optimal usage.

I'm planning to use it for making panoramas of my 3d renderings and mainly I'm not sure whether I should render the 6 cubic images separately or a just one spherical one. I use 3ds Max for the job and it has ready made tools for creating spherical panos (panorama exporter and the WrapAround lens shader). There are no tools for spitting out the cube faces automatically, afaik, one needs to do that manually but it's not very difficult either.

I was under the impression that cubic would be better, but then I read this and now I'm a little confused

So which is better? Is there a big difference? I am testing this myself as I write this, but renders take a while and all tips would be greatly appreciated.

Thanks for the reply!

I'm just doing some tests here with a checker texture on everything and indeed the 6 faces seem a little better in terms of twisting, although the spherical image isn't totally terrible either.

When doing the 6 faces separately there is a slight problem with Final gather (indirect lighting)- my test room has lights only on one side of it, and the difference in lighting is very noticeable - you can clearly see the edges of the faces - but it's probably something I can fix with a little tweaking.

I just put a test pano to my website - you can check it out here

I think I got the FG problem sorted almost - you can still see some seams there, but using a different method for calculating it helped a lot.

The main issue now is the ceiling and the floor - If you look up or down, you will see the obvious seam - any tips for getting rid of that?

I used a camera with a fov of 90 degrees to render the cube faces in Max. Other than that it's pretty much defaults, except that I replaced the maxpixelzoom attribute with a fovmax="75.0" - this was based on an earlier discussion here, additional tweaking suggestions are most welcome :)

For comparison, check out the same panorama as it comes out of Max's Panorama Exporter tool - here

Everything should be the same, except now the input image is a single spherical image. You can see the seam on the floor is gone, but overall the quality is crap compared to the cube faces version - any tips for how to get the best of both worlds? :)

Thanks,

Yes, I just downloaded the newest version (before the first post), so these are all made with that. I'm sure it does chop the spherical image to cube faces in the process, but still there's a significant difference in the results. It would be great to get the sharpness of the cubic example and yet get rid of the seams :)

Thanks,

I'll check and make another test tonight. I just realized that my "floor face" might be rotated incorrectly - I'll check that as well...

Hello again,

I tried with actual materials for a change - it took ridiculously long to render, but here is the resulting pano .

The problem with the floor and the ceiling was indeed my stupid mistake with the camera - they were rotated incorrectly. I checked out the link, Jarredja, and I tried to make some changes in the config - mainly I increased the jpg quality to 100 and the sampling to its maximum.

This was made out of 6 1024x1024 images and you can see the resolution is still rather poor. I welcome any tips for making this look better!

Currently the maxfov is at 50, because higher values seem to distort the room easily, but perhaps it's a little too low now. The room is supposed to be about 7,5 meters in length and about 2,5 meters high. This is a test, but it's a rather typical situation, so I'd really like to tweak this to look as nice as possible :)

Thanks for the reply,

I will try to do 2k cube faces next time - I must see if I can back down a little on some materials, because right now it wont even render completely over night! Or get a faster computer :D

What about the settings for the player? Are there any rules of thumb for indoor panoramas like in my example? (square-ish room) I've been playing mainly with the maxfov setting, but I have no idea if I'm doing this right. The goal for me is to get as natural looking projection as possible.

Cheers,
Vasco

Hi,

Awesome example! It's just the kind of thing that I want to be able to offer my clients.

Yes, I suppose 6 images can get really frustrating if a lot of post work is required. For these primitive tests that I have made, I've been mainly trying to maximize image quality (apart from the obvious lack of resolution) and minimize distortion. In an actual production I will definitely consider a spherical render!

I think I also need to be a little more careful on my material settings if I am to render 6k images ;)