Fix SSR orientation issues when using orthogonal camera

[mertkasar]

• Fixes: Vulkan: Screen space reflections weirdly rotated with orthogonal cameras #79002

Negative view space reconstruction was causing reversed screen space reflection rotations when using the orthogonal camera. The fix should not affect perspective.

[clayjohn]

As discussed on RocketChat. Feel free to force-push to this PR with your additional fix to ensure that the reflections don't use perspective projection. I am happy either way!

[mertkasar]

Regarding the second commit:

SSR shader were using a view direction value calculated from the view space when raymarching, which produces perspective on the reflection with lower camera z-depths. Using a constant -z view direction solves this issue.

Screenshots and an MRP can be found here: #79002 (comment)

[clayjohn]

Looks great! The final step before merging is to squash all the commits together so that the whole PR only contains 1 big commit with all your changes. We like to merge one commit at a time to keep the git history clean and navigable.

If you don't know how to do that, we have a helpful tutorial in the official documentation https://docs.godotengine.org/en/latest/community/contributing/pr_workflow.html#the-interactive-rebase

[mertkasar]

Oh, I see, that's why you mentioned force pushing 😅 On it.

[clayjohn]

Looks great! Thank you for the quick fix

[Calinou]

Tested locally, it works as expected.

Before

ssr_ortho_before.mp4

After

ssr_ortho_after.mp4

[akien-mga]

Thanks! And congrats for your first merged Godot contribution 🎉