Dual-paraboloid environment map to/from cubemap

oXYnary

Does anyone know of a program that will convert a dual-paraboloid environment map to cubemap or vice versa? That or know of a scene that is in both formats. Basically to engine match for testing of IBL vs like Marmoset or Substance.

Joost

This might be of some use to you, though I'm pretty sure it doesn't support DPEM http://www.flamingpear.com/flexify.html

Maybe you could try cutting it in half and processing both as mirror balls and then stitching the 2 results together as equirectangular or cubemap?

Eric Chadwick

Bixorama might work for you. However when I tested it a couple years ago, they were adding small seams along the edges.
http://www.outerspace-software.com/bixorama

Lys might also work, not sure if they support DP.
https://www.knaldtech.com/lys/

CGTextures uses Pano2VR to make their skies.
http://gardengnomesoftware.com/pano2vr.php

PTGui is free, does a bunch of operations.
http://www.ptgui.com/

kodde

Flexify which ha been mentioned has lots of crazy layouts to switch between.

oblomov

Sorry for not answering directly the original question, but if it is for engine comparisons, in Substance Designer and Painter, we don't use dual parabolic images but latitude-longitude panoramas. I'm not sure about Marmoset, but as far as I know they also read latitude-longitude panoramas (but maybe they convert them to dual-parabolic internally).

oXYnary

oblomov wrote: »

Sorry for not answering directly the original question, but if it is for engine comparisons, in Substance Designer and Painter, we don't use dual parabolic images but latitude-longitude panoramas. I'm not sure about Marmoset, but as far as I know they also read latitude-longitude panoramas (but maybe they convert them to dual-parabolic internally).

Actually that is a great point. Do you have a site that explains the difference between a lat/long (Equirectangular) vs a parabolic for IBL? We were under the assumption it was using a parabolic for the IBL in substance.

We had assumed they were parabolic because of this:
http://http.developer.nvidia.com/GPUGems3/gpugems3_ch20.html

Cant find anything on Nvidias site at least explaining that versus Lat/Long.

Is sphericial IBL the same as Equirectangular?
http://cgvr.cs.uni-bremen.de/teaching/cg_literatur/Spherical,%20Cubic,%20and%20Parabolic%20Environment%20Mappings.pdf

oblomov

The lat/long parametrization is the same thing you do when you draw a map of earth with the latitudes being horizontal even spaced lines and the longitudes being vertical even spaced lines. It's convenient to use for storage and editing but it's not often used directly in shaders because it has very high distortion around both poles (that's the reason why Groenland looks much larger on those maps than it is in reality) and is difficult to implement in hardware.

There's a bit more detail here (section 17.4.1) and here.

kirdaybov

I've made a Panorama Cubemap Converter which I'm trying to pass Steam Greenlight with. Check it out. I'd love to hear suggestions to make my software better. And I need upvotes to be able to distribute it.

Here's a link: Panorama Cubemap Converter