Ambient Cubemap For Global Postprocess Tilted

anonymous_user_2b4b7cf4 · October 27, 2014, 1:42pm

Ambient Cubemap For Global Postprocess Tilted - I’m not sure if this is due to the fact that I am using a panoramic image and not a true cubemap. Is that why the image is tilted? Is there anyway to control the orientation for this type of map?

anonymous_user_6e7b421a · October 29, 2014, 3:07pm

Hello NickZucc,

Your tilt probably is being caused by your picture not being a power of two i.e. 512x512 or 1024x1024. Try re-scaling/re-sizing your image to see if this resolves your issue. Here is some documentation on using Ambient Cubemaps versus using a Skylight and how to optimize each just for your own personal information:

Hope this helps!

anonymous_user_2b4b7cf4 · October 30, 2014, 3:35am

Thanks for this! I will give this a go!

anonymous_user_2b4b7cf4 · October 31, 2014, 2:11am

So I was able to do a test, saved out 2 version in Photoshop 2048 X 1024 and a 1024 X 1024 and both have the same effect. The scene is still tilted. I just took the lighting value for the map and cranked it up and put the scene into detail lighting mode (Alt + 5) and you can clearly see this is still a problem.

anonymous_user_2b4b7cf4 · October 31, 2014, 5:36pm

Could anyone else please verify real quick if this is happeninng to them as well? Thanks!

anonymous_user_2b4b7cf4 · November 5, 2014, 1:04pm

Andrew, are you able to comment on this? Will this not have an effect on lighting due to the tilt?

anonymous_user_6e7b421a · November 5, 2014, 4:30pm

Would you mind sending me your Cubemap texture file so I can test your specific image?

anonymous_user_2b4b7cf4 · November 10, 2014, 5:07am

AndrewHurley, Sorry about that, I didn’t see this post. Here is a link to the images on my dropbox account:

https://dl.dropboxusercontent.com/u/2252767/Unreal/HDRI_TestFiles.zip

There are 3 different sizes, Orig, 2048X2048 and 1024X1024

anonymous_user_6e7b421a · November 10, 2014, 2:51pm

Hey again NickZucc,

So I attempted to reproduce your issue, but with no luck. I tested all three texture files and was not experiencing any sort of tilt that you are seeing. In order for me to assist you further I will need some specific steps to follow that you are doing to get the tilt.

Let us assume I am starting from a blank default map and have already imported your three texture files into the content browser. From there if you could, please walk me through what to do next.

Thanks!

anonymous_user_2b4b7cf4 · November 10, 2014, 3:06pm

Andrew, Here are my steps. I load up my project and then:

Make a new blank level. (I am using the blank map to make sure there is nothing else contributing to this.)
Make a PostProcessVolume. (I Make it unbound to effect the entire level.)
In the PostProcessVolume I turn on the Intensity for the Ambient cubemap. (Intensity is set to 1.)
Then I select the texture/hdri map and plug it into the ambient cubemap texture slot. (In this case I used the original sized texture that wan’t square.)
Then I put the editor into detail lighting mode to see the map applied to the world. (Alt + 5) And the world is still tilted.
Then I try the 2048X2048 and 1024X1024 map in the ambient cubemap texture slot and the problem is still persist

Thanks!

anonymous_user_6e7b421a · November 10, 2014, 3:32pm

Just to make sure, by blank level do you mean “Default Level” with the bare minimum things in it like the player start, directional light, height fog, and a floor mesh?

Or do you mean “Empty Level” with literally nothing in it?

anonymous_user_2b4b7cf4 · November 10, 2014, 3:55pm

Empty with nothing in it.

anonymous_user_6e7b421a · November 10, 2014, 4:16pm

Ok great, so I tested your images again in the empty level and was able to get the results you are talking about. I went back to the documentation to see if there was anything there that could help point out why the orientation is getting skewed.

I found this and wanted to make sure you had imported/unwrapped into the sphere format correctly?

anonymous_user_2b4b7cf4 · November 10, 2014, 11:51pm

Yes, as far a I know, that is the format that I am using. Is this just a bug??

anonymous_user_6e7b421a · November 11, 2014, 2:54pm

Hello again NickZucc,

Yes, as of now I have made the developers aware of this issue and a bug report has been created. Thank you for your patience on this matter and I appreciate the steps and documentation your provided to me in order for us to log this as such.

One work around I can suggest is to use a Sky Light instead of an Ambient Cubemap for your ambient occlusion lighting, especially when using the sky’s lighting.

Thanks again,

anonymous_user_4b93dca7 · November 11, 2014, 10:56pm

We cannot reproduce it with the .hdr
It looks like the texture is imported properly.

AmbientCubemaps don’t automatically create a skybox - if you want that you either need to make a material looking up the ambientcubemap or you setup some funky inverse reflective materials (full metallic, far sphere mesh, normals are output inverted).
I assume you see the cubemap in a reflection of some object and that is rotated because the normals there are tilted.
That also would have affect on point lights.

anonymous_user_2b4b7cf4 · November 12, 2014, 12:48am

OK, I’m not sure what this means as far as how it lights the world. I don’t really care what the preview looks like, I just want make sure that it isn’t lighting and reflecting into the world at this funky angle.

So if you can’t reproduce this, it makes me wonder if this is because this bug existed in an earlier version of the engine and is still present because I have been working on this project for about 3 + versions now? Well…thanks for looking into things.