Background Problem

[ntxdave]

OK guys, I have been using TR V2 for several years. I am suddenly having a problem with the background for a render. If you look at the image below, you will see that I have set the background type to spherical sky but in the image, you do not see the background image. What the heck am I suddenly doing wrong?

TR Background Problem.jpg (215.19 KiB) Viewed 10814 times

BTW: I do not have anything at all under the model like a rectangle with a material assigned, an infinite plane or anything else.

[Chris]

What version of TWR are you using?

[ntxdave]

I am running 2.17.12

BTW: There is another post where someone else is have environment problems.

[ntxdave]

OK - I think I have figured out the problem. It is the camera setting. In the image below, you will notice:

• In the top screen captures, you will notice that the camera setting is Parallel resulting in it ignoring the Spearical Sky setting and rendering the image with a black background.
• In the bottom screen captures, you will notice that the camera setting is Perspective resulting in it applying the Sperical Sky setting and rendering the image with the HDRI background.

Render-Background.jpg (378.38 KiB) Viewed 10793 times

[Chris]

I wanted to make sure we didn't introduce a new problem with the most recent release. I will take a look at the orthographic projection vs perspective issue. It's not something we were previously aware of.

[ntxdave]

Thanks Chris. By orthographic do you mean Parallel?

BTW: I have not seen this problem in the past.

[Chris]

Hi Dave,

So I can confirm that, yes, using the Parallel Projection camera (also known as orthographic projection) with a spherical sky will produce the results you see. This is undoubtedly because the way a spherical sky is mapped into the 3D world just isn't compatible with the idea of parallel projection.

I can confirm that using the 'Background' image types will render as expected, if you really need a Parallel render with a background image.

[Chris]

I can't say I have seen this before but I never use Parallel so it's probable it's been there this whole time...

[ntxdave]

I do not think it has. I will have to go find some older models to try to verify.

Ugh, could not find any renders but all of my "old" models were done in Parallel.

I did try the Two Point perspective and it also worked. The only one that did not work was the Parallel Perspective. Something else interesting this morning was that when I did the Parallel Perspective today, it gave me a medium green background (like my original post that started this thread) instead of the black one yesterday (as seem in the image I posted). Here is what it created today.

Render-Parallel-green.jpg (107.62 KiB) Viewed 10753 times

[ntxdave]

I did some more testing this morning relative to camera set to Parallel Projection. What I have found is that it seems to work OK is you use an HDR file with the Hemispherical Sky, Spherical Sky and Sky Probe. However, if you use a JPG file as the background with those three settings it will not use them as the background. Instead, it seems to use your default background color you have set up with Twilight Render (i.e. background color when you select Background Color as the Background / Sky Type).

Just to confirm if you have the camera set to either Perspective or Two-Point Perspective then using a JPG file with the Hemispherical Sky, Spherical Sky or Sky Probe it will work (image may be skewed in some cases though).

Hope all of this is clear. Once again, I am hoping to get some feedback from Twilight Render if this is the way it is supposed to be.