Rift Ray-tracing

Just caught wind of this thread. Very nice work, TeraBit.

"cybereality" wrote:
Just caught wind of this thread. Very nice work, TeraBit.

Thanks Cyber.

I've tried to calibrate it according to the World Demo, moving the images 56 Pixels inward.

"TeraBit" wrote:

"cybereality" wrote:
Just caught wind of this thread. Very nice work, TeraBit.

Thanks Cyber.

I've tried to calibrate it according to the World Demo, moving the images 56 Pixels inward.
...

That image shows a HUGE improvement. The radial distortion needs to be reduced a little, because in the Rift, the wall appears to be bulged toward the viewer a bit.

Perhaps we could do this like an eye exam, where you post a pair of images and I (or other Rift owners) say which one is better, and you replace the bad one and republish (binary search). Or somebody with a Rift could apply pincushion distortion to the published image above so it looks good in the Rift, then publish it to be used as an "out of Rift" reference for adjusting the ray-trace lens model. Or perhaps you can adjust your model by inverting the Rift distortion coefficients...

Also, I can see the outer horizontal black borders when I look in the other direction, so you could widen your ellipses a bit into true circles. They look narrower than they should be.

But it is easy to view now, and that shows great progress!

Ok, updated the image in the post above with a larger circle and lower distortion...

"TeraBit" wrote:
Ok, updated the image in the post above with a larger circle and lower distortion...

Much better. Still a little bulge in the center, so need to reduce distortion even more (for my Rift lens settings).

And I can clearly see that clipped left edge as a black border, so you need to extend that so it is round again.

But it is a big improvement over the previous image.

Ok, left clipped edge sorted and lowered bulge.. 8-)

This is looking fantastic! Don't have my Rift with me atm so I can't comment on how it looks in 3D, but the images alone are compelling me to explore this room!

I do have a general question, though. Why all this tweaking to get the image correct? Can you not use the shader provided by Oculus in the SDK as a base, and work through the distortion calculation from there? Seems like you have the information available to distort exactly like the Unreal or Unity SDK without needing to tweak bulges, overlap, etc. I haven't tried to implement Rift support manually, so I may be missing something! Are there gaps in the SDK that you have to fill in yourself when doing custom engine integration?

Glad you like the image, it's only running basic RT at the moment. (I Don't have my Rift yet either (still processing :( , but anyone with one is welcome to give feedback on how the images look in VR).

The way Ray Tracing and Rasterisation create images is very different. In this case, rather than warp a 2D texture (which I could do at display time), I am simulating the lenses of the rift in the Ray Projection code, so it's almost the opposite of the warping.

The payoff is that you project less rays overall and even do cool stuff like only anti alias in the middle or reduce detail as it gets to the periphery. (I've not done any of that yet.)

That makes sense, thank you! Very cool -- I have a soft spot for ray tracing :) Will be watching this develop.

Scratch that... The video got messed up... :(