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Martin Griffiths

@Griff_ • 7,870 subscribers

#NoMansSky Engine Programmer. Owner of #TrickyPixels who re-mastered #JourneyPS4. Platform lead on #ProjectCars and EA’s Harry Potter games. BAFTA member

Shorts

As a graphics engine coder I think when you look at a flickering bug like this one in the video below it’s not immediately obvious what is going on. The key here is observation - to study this flickering/bugged render carefully - what do we see? Firstly for me it was very obvious that nearly all of the scene shadows were flashing on and off - but (but!) there was a secondary issue where some buildings and parts of the sky were also flashing purple. Hmmmm. Interesting. I initially thought then this might be two separate bugs - but because the sky purple element could only based on full screen post fx and not 3D rendering I looked at this first with a few GPU captures to step through all our post processing to find the rendering stage which made these pixels turn purple: When I did this I found the colour 3D texture LUT grading that makes our different biomes have unique colour palettes was going very wrong - colours near 0 or 1 were wrapping and making the purple elements that we see in the said sky and base parts. The only way this could happen was if the texture was corrupt (which it was not) or if the 3D texture sampling was wrapping and not clamped as intended. That was the Eureka moment - because if the post fx had the wrong texture sampler then the disappearing shadows which also require an exact texture sampler for comparing depth might be also wrong because of the same kind of texture sampling issue! So with this idea that the engine was using the wrong texture samplers, but only in very high draw call scenes like the big base here I the looked at some engine limits and found the bug very quickly - a circular dx12 descriptor buffer for samplers running out over multiple frames, reusing the wrong data for new scenes inflight. Hence the flickering, as the GPU randomly got wrong samplers for some post textures or shadow depth. Easy to fix with triple limits for future expansion and also adding an assert/debug spam in case this limit is ever reached again - QA testers would see this message and report if they ever saw a flicker with this style of bug. My bug and my bad from 2017 porting NMS to DX12 without foreseeing how massively complex bases and our game would grow.

As a graphics engine coder I think when you look at a flickering bug like this one in the video below it’s not immediately obvious what is going on. The key here is observation - to study this flickering/bugged render carefully - what do we see? Firstly for me it was very obvious that nearly all of the scene shadows were flashing on and off - but (but!) there was a secondary issue where some buildings and parts of the sky were also flashing purple. Hmmmm. Interesting. I initially thought then this might be two separate bugs - but because the sky purple element could only based on full screen post fx and not 3D rendering I looked at this first with a few GPU captures to step through all our post processing to find the rendering stage which made these pixels turn purple: When I did this I found the colour 3D texture LUT grading that makes our different biomes have unique colour palettes was going very wrong - colours near 0 or 1 were wrapping and making the purple elements that we see in the said sky and base parts. The only way this could happen was if the texture was corrupt (which it was not) or if the 3D texture sampling was wrapping and not clamped as intended. That was the Eureka moment - because if the post fx had the wrong texture sampler then the disappearing shadows which also require an exact texture sampler for comparing depth might be also wrong because of the same kind of texture sampling issue! So with this idea that the engine was using the wrong texture samplers, but only in very high draw call scenes like the big base here I the looked at some engine limits and found the bug very quickly - a circular dx12 descriptor buffer for samplers running out over multiple frames, reusing the wrong data for new scenes inflight. Hence the flickering, as the GPU randomly got wrong samplers for some post textures or shadow depth. Easy to fix with triple limits for future expansion and also adding an assert/debug spam in case this limit is ever reached again - QA testers would see this message and report if they ever saw a flicker with this style of bug. My bug and my bad from 2017 porting NMS to DX12 without foreseeing how massively complex bases and our game would grow.

72,701 views

Recently we had a bug on Switch where NPC interactions (which have Depth of Field) caused a horrible crawling black pixels bug. We saw reports of a similar bug with certain AMD 7xxx series cards with #NoMansSky Worlds Part II, but until this week hadn’t been able to reproduce this issue - our players reported various semi fix methods with AA modes and windows settings, adding to the mystery. I reproduced the bug yesterday after finding a YouTube link on Reddit that happened to show their full graphics settings! You can see the bug here in my quick phone capture of the horror bug! 4 hours of shader debugging later and I have submitted a fix which should make it into the next patch. On the surface this bug looks the same as the Switch issue which was NaN propagation - but it wasn’t: Interested to see if any graphics programmers here can have a stab at what the bug is, bearing in mind it was on one class of GPUs only.

Recently we had a bug on Switch where NPC interactions (which have Depth of Field) caused a horrible crawling black pixels bug. We saw reports of a similar bug with certain AMD 7xxx series cards with #NoMansSky Worlds Part II, but until this week hadn’t been able to reproduce this issue - our players reported various semi fix methods with AA modes and windows settings, adding to the mystery. I reproduced the bug yesterday after finding a YouTube link on Reddit that happened to show their full graphics settings! You can see the bug here in my quick phone capture of the horror bug! 4 hours of shader debugging later and I have submitted a fix which should make it into the next patch. On the surface this bug looks the same as the Switch issue which was NaN propagation - but it wasn’t: Interested to see if any graphics programmers here can have a stab at what the bug is, bearing in mind it was on one class of GPUs only.

28,757 views

I saw this video from Vazillia last week and was puzzled - We hadn’t noticed this quality regression with PSSR/PS5 Pro, but the bug reproduced on my dev kit, right away. 6 hours of debugging later, I worked out what went wrong and a fix made into the current 6.04 patch!

I saw this video from Vazillia last week and was puzzled - We hadn’t noticed this quality regression with PSSR/PS5 Pro, but the bug reproduced on my dev kit, right away. 6 hours of debugging later, I worked out what went wrong and a fix made into the current 6.04 patch!

14,740 views

On PS5 quite a few people reported this horrible visual bug with water and underwater base parts, affecting both VR and flat-mode. A fix is now in today’s experimental build and should make it to a future patch. My bug - rolling eyes when I found it.

On PS5 quite a few people reported this horrible visual bug with water and underwater base parts, affecting both VR and flat-mode. A fix is now in today’s experimental build and should make it to a future patch. My bug - rolling eyes when I found it.

26,401 views

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Love your demo つよし723 パイロット - I'm not sure if you saw this #NoMansSky debug camera video I made last year. Blazing between 3 planets in 50 seconds.. a nice example like yours, of how seamless and powerful our engine is! (PS5 running here, with video from an iPhone…)
0:49
Griff_'s profile picture

Love your demo つよし723 パイロット - I'm not sure if you saw this #NoMansSky debug camera video I made last year. Blazing between 3 planets in 50 seconds.. a nice example like yours, of how seamless and powerful our engine is! (PS5 running here, with video from an iPhone…)

Martin Griffiths

16,498 views • 8 days ago

In a past life at EA I worked for 8 years on the engine for the Harry Potter games - in 2006 it was a formative time because Order of the Phoenix was the first fully streamed, open world game that we'd made : from an old sd card.. the first time Harry ran around Hogwarts on PS3!
1:18
Griff_'s profile picture

In a past life at EA I worked for 8 years on the engine for the Harry Potter games - in 2006 it was a formative time because Order of the Phoenix was the first fully streamed, open world game that we'd made : from an old sd card.. the first time Harry ran around Hogwarts on PS3!

Martin Griffiths

620,622 views • 1 year ago

This is probably a bug, but quite a good looking one! Water goes a bit crazy if you beam down into it - causing quite a cool visualisation of our newer water physics.
0:23
Griff_'s profile picture

This is probably a bug, but quite a good looking one! Water goes a bit crazy if you beam down into it - causing quite a cool visualisation of our newer water physics.

Martin Griffiths

262,795 views • 9 months ago

I’ve seen quite a lot of debate recently about loading times and smoke and mirrors in space games - so thought I’d show you all the #NoMansSky debug camera .. a nice demo of how seamless and powerful our engine is! PS5 running here, with video from an iPhone… 3 planets in 50 seconds.
0:49
Griff_'s profile picture

I’ve seen quite a lot of debate recently about loading times and smoke and mirrors in space games - so thought I’d show you all the #NoMansSky debug camera .. a nice demo of how seamless and powerful our engine is! PS5 running here, with video from an iPhone… 3 planets in 50 seconds.

Martin Griffiths

447,474 views • 1 year ago

In the #NoMansSky Worlds Part II trailer there’s a lovely sequence with multiple ships creating water wakes as they fly - here’s the first time 5 months ago that our talent graphics coder(Tom) demonstrated a ship’s wake on a still water surface. Blown away then and even more now!
0:20
Griff_'s profile picture

In the #NoMansSky Worlds Part II trailer there’s a lovely sequence with multiple ships creating water wakes as they fly - here’s the first time 5 months ago that our talent graphics coder(Tom) demonstrated a ship’s wake on a still water surface. Blown away then and even more now!

Martin Griffiths

193,410 views • 1 year ago

“Hello, boys! I'mmm BAAACK!” (Credit Reddit u/Vilxir) #NoMansSky
0:49
Griff_'s profile picture

“Hello, boys! I'mmm BAAACK!” (Credit Reddit u/Vilxir) #NoMansSky

Martin Griffiths

41,955 views • 6 months ago

Today. I was doing some work on improving PSVR2 in #NoMansSky and managed to get myself the double (distortion) foveated bug again! PSSR though… made it look even better than before, so I had a walk around the station..
0:42
Griff_'s profile picture

Today. I was doing some work on improving PSVR2 in #NoMansSky and managed to get myself the double (distortion) foveated bug again! PSSR though… made it look even better than before, so I had a walk around the station..

Martin Griffiths

50,805 views • 9 months ago

For people asking about the “rare graphical glitch that caused some creature models to explode”… here’s a video showing the bug - it’s one that I fixed and was caused by certain creatures with fur when rendering them as a hologram - a silly bug with the “shells” geometry shader
0:28
Griff_'s profile picture

For people asking about the “rare graphical glitch that caused some creature models to explode”… here’s a video showing the bug - it’s one that I fixed and was caused by certain creatures with fur when rendering them as a hologram - a silly bug with the “shells” geometry shader

Martin Griffiths

54,708 views • 1 year ago

At 18 years old, around about 1990/91 and just a few years into learning 3D graphics I worked with a friend, the late Jose Commins to create our first 3D world on the Atari ST. It might seem primitive and crude, but this was a foundational step for me from there to #NoMansSky
1:11
Griff_'s profile picture

At 18 years old, around about 1990/91 and just a few years into learning 3D graphics I worked with a friend, the late Jose Commins to create our first 3D world on the Atari ST. It might seem primitive and crude, but this was a foundational step for me from there to #NoMansSky

Martin Griffiths

34,936 views • 1 year ago

“KITTY!!!” #NoMansSky ShipBuilds. (Credit Reddit u/Str8TripNOuT)
0:42
Griff_'s profile picture

“KITTY!!!” #NoMansSky ShipBuilds. (Credit Reddit u/Str8TripNOuT)

Martin Griffiths

18,370 views • 8 months ago

You can see here how Elite directly influenced me - 5 years later after this club, aged 16 I wrote my first 3D code for this vector screen demo on the Atari ST. I would not have written this and would not have ended up working on #NoMansSky if Elite had not existed! #elite40
4:59
Griff_'s profile picture

You can see here how Elite directly influenced me - 5 years later after this club, aged 16 I wrote my first 3D code for this vector screen demo on the Atari ST. I would not have written this and would not have ended up working on #NoMansSky if Elite had not existed! #elite40

Martin Griffiths

23,502 views • 1 year ago

#NoMansSky Beacon 5.75 is releasing now on all platforms - amongst the other fixes, it contains a fix for a PSVR2 only bug that was exceptionally difficult to track down. I probably spent more than 15 hours on this one, which caused flickering on some types of grass and trees!
0:29
Griff_'s profile picture

#NoMansSky Beacon 5.75 is releasing now on all platforms - amongst the other fixes, it contains a fix for a PSVR2 only bug that was exceptionally difficult to track down. I probably spent more than 15 hours on this one, which caused flickering on some types of grass and trees!

Martin Griffiths

12,436 views • 10 months ago

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