Polyphony Digital Reveals GT Sport's "Iris" Ray Tracing System at CEDEC 2018

True, real-time ray tracing is a ways off. Even the new nVidia chipset and DirectX implementation is extremely limited. And by a ways off, I'm mean a WAYS off. Think 15-20 years. Unless there's some kind of tech breakthrough that brings significantly more computing power to the table. That said, I'm happy to get whatever we can get.
 
Baking all of this ray-traced data in only 30 minutes is very impressive though, and would explain how all tracks including new additions have 6-7 multiple time of day settings that look great. Shows PD's always thinking ahead with their tech r&d to improve development workflow, and the development time really just depends again on actually 3D modeling everything. Glad they're (seemingly) now starting to outsource?

The global illumination light data with PD's material work in GTSport is fantastic.



Once the advancement of real-time raytracing comes I expect most racing games will end up being graphically on par with each other outside of art differences though.
 
queleuleu
Ligthing was always the strong point of GT. But this could be a revolution in GT history if true.

Physics Engine Development Engineer

・Development of a rigid body simulator
・Development of an elastic body simulator
・Development of a fluid body simulator
・Development of a rag doll simulator
・Development of other physics simulators
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GT5 had a pretty good visual damage system,it just needed to be toned down a bit because it had the tendency to create some nightmare fuel cars

Exhibit A: The Cursed Ferrari
1505169-gt5_bestbuy_damage_round2_9.jpg
 
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PettyWingman
I'm really impressed by the metal reflection in the ray tracing rendering.

Did anyone notice that in ray tracing, the car's body and the instrument panel reflects the parts of the car?
(Can anyone understand my poor English?)
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Yep because that is one of the purposes for that technology.

You will see that on PC with the Nvidia RTX cards in Assetto Corsa Competizione in the coming months.
 
ShawnPhillips
Depends on if the PS5 is capable of real time raytracing Similar to NVidia RTX. If it can then dynamic time of day would be possible with GT sports level of graphical fidelity. If not then Raytracing can still be used to make super realistic looking pre-baked lighting at the expense of dynamic time of day.
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Wasn't there rumors sony were working exclusively with nvidia on the ps5 architecture?
 
GT games have always had fantastic lighting, & GT Sport is no exception; it's still class leading. However, I think I'd prefer more cohesion between shadow & lighting than having kick ass lighting at the expense of poorly rendered shadows. Either way, it's great to get some more insight into this very closeted studio. Hopefully they'll open up more & more about these things, which can only help us to appreciate the hard work & innovation that goes on behind the scenes. Fascinating stuff...


👍
 
Auditore
...i keep wondering if rain in GTS is taking so long because they are trying to keep 60 FPS locked.
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...I'm wondering TBH if rain will come at all, I mean, we have one event with wet track, but there are no rain drops etc...

And knowing Kaz and his vision of graphical fidelity and realism, I doubt that it will be doable... Wouldn't mind if they get hands on coders from Driveclub :D
 
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The offline ray-trace stuff is cool, I expect they've been using something like it for a long while, one way or another. I mean, Quake 2 basically had it... ("radiosity") They also had image based lighting since GT3 / GT4, which is a very primitive "ray-trace" into a pre-made cube map, effectively.

Interestingly, they also mention pre-computed radiance transfer (PRTF), which is usually a way of getting a real-time solution to the "global illumination problem" (for which ray-tracing is still something of a "brute force" approach). Note that GI is short for global illumination, and indeed it looks a lot like some of the shots are contrasting this particular tech separately from the offline ray-tracing proper. So GT Sport has GI in the form of PRTF for car interiors, is what seems likely, which is reassuring (not least because we suspected they would back in the PS3 days, what with the interior shadows problem then).

There's also a focus on offline "baking" helping out with ambient occlusion issues, which is also effectively a GI concern. Wish I could read it all properly, looks like they do something funky with a shadow map type process. I think this incompatibility of a fast and general GI implementation and detailed shadows and the like is what killed off the dynamic time of day.

If nothing else, some of the more computationally expensive techniques could come to the photomode, or perhaps even the menus, which would be pretty rad.
 
I'm glad there's no time of day. GT Sport wouldn't be the best looking racing game ever while being locked 60 fps if it had dynamic time and weather changes. I'd rather see an ultra polished graphically superior to everything not named Uncharted 4 than a decent looking GT with weather and time features most people wouldn't use anyways.

It would be better to have more times selectable though. All tracks should have night modes, and static weather
 
919 Hybrid
The most cursed thing about this is that I'm pretty sure that's a Ferrari 458
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I thought it was a Ferrari then i edited my comment thinking it was a Lambo

rex1825
...I'm wondering TBH if rain will come at all, I mean, we have one event with wet track, but there are no rain drops etc...

And knowing Kaz and his vision of graphical fidelity and realism, I doubt that it will be doable... Wouldn't mind if they get hands on coders from Driveclub :D
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Driveclub was amazing.....at 30 FPS,which is a way PD can no longer go back,i wouldn't mind rain races to be locked at 30 FPS but i doubt the majority of the fanbase would like it.
 
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Auditore
Driveclub was amazing.....at 30 FPS,which is a way PD can no longer go back,i wouldn't mind rain races to be locked at 30 FPS but i doubt the majority of the fanbase would like it.
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Depends on who you ask. A lot of people dont mind 30fps, some throw a fit at any less than 60.
 
I used to say I didn't mind, that I couldn't tell. Then I left Driveclub to play GT Sport and can't go back. I loved Driveclub too, got the bikes version and all DLC. It's not the look or way it moves but 60fps feels more engaging and responsive.

I think much as I want actual rain some of the time of day settings already have ominous clouds, they could easily just do a baked in "British Day" setting with grey overcast sky and damp ground but no real rain, just a foggy drizzle.
 
Cerebral303
I used to say I didn't mind, that I couldn't tell. Then I left Driveclub to play GT Sport and can't go back. I loved Driveclub too, got the bikes version and all DLC. It's not the look or way it moves but 60fps feels more engaging and responsive.

I think much as I want actual rain some of the time of day settings already have ominous clouds, they could easily just do a baked in "British Day" setting with grey overcast sky and damp ground but no real rain, just a foggy drizzle.
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I love 60 FPS racing games but i don't have a problem playing Driveclub,your brain get used to the FPS,the problem is when you have the same game with certain modes that use 60 FPS and another mode that uses 30 FPS that might be very jarring.
 
Auditore
I love 60 FPS racing games but i don't have a problem playing Driveclub,your brain get used to the FPS,the problem is when you have the same game with certain modes that use 60 FPS and another mode that uses 30 FPS that might be very jarring.
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Totally agree with this. Uncharted 4's multiplayer mode ran at 60fps while the survival mode was at 30fps. It isn't really bothering until you switch between the two and then it becomes very noticeable and jarring.
 
Lee x sensai
Imagine the game on PC :bowdown::bowdown:
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You could say that about any other Sony exclusive

Salty66
Totally agree with this. Uncharted 4's multiplayer mode ran at 60fps while the survival mode was at 30fps. It isn't really bothering until you switch between the two and then it becomes very noticeable and jarring.
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And it's even more jarring in a racing game because you're always at high speeds
 
Cerebral303
I used to say I didn't mind, that I couldn't tell. Then I left Driveclub to play GT Sport and can't go back. I loved Driveclub too, got the bikes version and all DLC. It's not the look or way it moves but 60fps feels more engaging and responsive.

I think much as I want actual rain some of the time of day settings already have ominous clouds, they could easily just do a baked in "British Day" setting with grey overcast sky and damp ground but no real rain, just a foggy drizzle.
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Dirt Rally has 60 fps rain in VR!

Of course without any cars to render and everything very low res. DriveClub couldn't do the rain in VR / 60 fps, nor dynamic time of day. You can still set the time yet it remains static during the race.

Dynamic time and weather does add to game play, shinier metal does not. I loved the variation in DC, different sky every time, different light and dark spots due to the clouds actually moving. Endurance races with dynamic time and weather kept the race interesting. I would love to do an endurance race on N24 with dynamic weather. GTS is so static you start using shadow lines as brake markers....
 
Perhaps the chance is slim but I remember Kaz said weather conditions will likely came to GTS, but not in short time. Maybe a year or so. Still "likely came" could mean it won't as we know some of Kaz prediction isn't exactly spot on.

Also, curious which raytracing model that technically is more powerful, PD own Iris or Kunos AC Competizione powered by Nvidia graphics software in comparison?
 
Wan Brasco
Can someone explain to me I have read 10 times but still don't get it
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Imagine you're in a room with only a single light bulb. And then there's a random dead dog that's in the same room. The light of the bulb will hit the dead dog, and it will reflect to your eyes. Ray tracing would try and simulate these light reflections to make much more accurate lighting
 
iucidium
And still, minus the palm trees - all trees are 2d sprites.
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Indeed, because that’s how you do it if you’re a clever 3D artist. It’s a terrible waste of resources to model a branch in polygons when it’s only part of the background and especially when you have a limit of 1/60th of a second to render the scene.
 
Alpha Cipher
Imagine you're in a room with only a single light bulb. And then there's a random dead dog that's in the same room. The light of the bulb will hit the dead dog, and it will reflect to your eyes. Ray tracing would try and simulate these light reflections to make much more accurate lighting
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And in theory Raytracing could shorten game development times(something we urgently need right now) because you don't have to spend time faking every reflection,Raytracing does all that for you
 
The drawback of not having time of day is something that PD should continue researching for their future graphics engine. The PS4 raytracing is definitely innovative, and further research on dynamic weather and time of day integration by means of realtime pre-render light changing as well as tree shadow movement from the sun's rotation via TOD is worth waiting for.

Can't wait for the next set of results if they do the research.
 

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