With RTX ray tracing could we "bake" FX lighting/shadow effects?

At the moment when you set of an explosion or FX you can add lights to it and they can produce shadows.

This of course will impact dynamic performance so you will limit these effects either through options or just to keep a good framerate.

What if like baked GI you could bake into FX the lighting and shadow data?

In theory massively reducing the performance impacts but allowing for a lot more realistic effects with pre-baked ray traced lighting and shadows.

Itā€™s lightprobe

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Yeah, this doesnā€™t need RTX at all, you can just do this now with things like light probes and imposters.

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The point of RTX is that it can be used dynamically at runtime. There is no need to add RTX support to bake time tasks.

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This. One of the major advantages to realtime raytracing is achieving realism with less effort than existing methods.

Performance is only truly a concern right now because weā€™re on first generation hardware. First generation hardware is always heavily restricted compared to subsequent generations. NVIDIAā€™s first graphics cards came out in 1995 but they didnā€™t gain hardware texturing and lighting until 1999.

https://en.wikipedia.org/wiki/NV1
https://en.wikipedia.org/wiki/GeForce_256

In fact because software rendering was both very good and nearly feature identical to a dedicated card they had to make the cards valuable in other ways to ensure sales. NVIDIAā€™s NV1 didnā€™t just rendering 3D. It handled sound playback and joystick controllers too. And even then it was just barely ā€œacceptableā€ in reviews because it wasnā€™t that good at any of it.

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Well itā€™ll also help offline baking. Indeed Unity used an RTX card for some great GI Copenhagen bake-off recently. Love those cupcakes.

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Is RTX baking lightmaps gonna happen?

It has already happened, Unity demonstrated GI baking, RTX accelerated at recent Unite. Itā€™s the easiest way to use the hardware, to accelerate existing workflows.

Substance is accelerated by it too, in fact I think most industries use it more for that still, that any serious gaming, at least until prices become sane and the next consoles pop up.

Interesting, so will RTX bakes supports full GI? TBH not too sure.

Why wouldnā€™t they?

I dunno mate thatā€™s why Iā€™m asking the question. Does it capture the subtle soft shadows and light bleeding enlighten did.

E.g my last enlighten test

5091029--501608--l2.jpg

RTX simply accelerates the baking so it would support whatever features the progressive lightmapper supports (GPU version).

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Ok thatā€™s good to hear. So it is basically like GPU LM but turbo charged? But obviously no time frame for its release yet I guess.

Few more questions, am I right in thinking the LM and the size of the scenes you load will be limited to the VRAM on the GPU as usual.

Does RTX support features like SSS?

NVIDIAā€™s RTX hardware only has one purpose and that is to trace the path the rays take in the scene. Anything beyond that like the way the light appears is handled with normal hardware.

https://en.wikipedia.org/wiki/Bounding_volume_hierarchy

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Ah OK I guess Iā€™m learning stuff, so I would need the HDRP sss shaders from the ā€˜book of the deadā€™ or something.

Can you explain the difference between RTX and DXR? Iā€™d like to know this stuff before I buy myself an raytracing box.

RTX is the trademark for the hardware acceleration implemented by NVIDIA. DXR is the trademark for the software APIs implemented by Microsoft. Neither is dependent on the other. DXR will support any hardware assuming the manufacturer has implemented support for it in their drivers.

Ah OK I just saw this article which was a decent read.

@hippocoder is there a talk / video on Unityā€™s YouTube channel that demonstrates light baking with RTX hardware?

Maybe they can concentrate on getting PLM to work at all :stuck_out_tongue: