Why I'm Excited - An overview of HDRP and CBT Studies

[foonix]

On 4/29/2023 at 9:56 AM, JoeSchmuckatelli said:

Have you seen the KSP2 / GDC talk?  There is a brief portion where they discuss HDRP & CBT. 

I'm curious as to what you think now that we've had several weeks. 

Can they do HDRP independent of the CBT work - or do they need to do both together? 

@RayneCloudany thoughts? 

I hadn't had a chance to really watch it but just remembered this was here

Can they do it independently?  I think so.  Nothing in CBT is married to HDRP.  Would they want to?  It's hard to say.  If I were in there re-engineering the system knowing I'd eventually have to do it in HDRP anyway, I might want to target HDRP in the first place.  Nothing jumped out at me as being impossible to do as part of the background render or in a custom render pass.  It's just that engineering the color sampling to work with both their current PBR and HDRP's PBR seems like a lot of unnecessary pain.

I learned a few other things watching though.  Apparently the artists wanted to control the ambient light map in a way that has different emphasis for things like specular bounce, and such.  They mentioned it is done from the cubemap sampling side, but for HDRP I believe the cubemap sampling is down in the guts of the HDRP/Lit shader, which has strict limits on what can be change about how light interaction works.  So this will probably have to be moved to the cubemap generation process, which can be controlled from code.  This throws some more complexity into the conversion process I hadn't realized.  They may have to use different materials to render the planet when doing it in the cubemap to get this kind of effect.. which is doable but needs retooling and then an art pass to re-evaluate what they're trying to do works.  But imagine something like this, potentially:  you pan the camera at the Mun surface and the stars fade out as the camera focuses on the surface detail, then look back up at the sky and the surface washes out a bit while a sky full of stars and Kerbin comes back into focus.

They mentioned that they control the directional light intensity based somewhat on the SOI.. that adds a lot of work I hadn't thought about.. at minimum will need an artist to take a pass at tweaking the levels for hdrp to get the desired look.  From their diagram, they're probably not really following the inverse square law, which is fine, but this tells me perfectly realistic lighting isn't the goal.

But HDRP could also open some opportunity to do things in ways that would have been hard with the current system.. they mentioned trying to adjust the light brightness to get a "moon landing" type feel to the images.  HDRP has a notion of camera exposure control, so this kind of thing can be done not only based on SOI but also auto exposure change based on what the light levels are in the camera.   Moon landing pictures where the stars aren't visible and the shadows are very hard, that is actually a byproduct of the interaction between the light levels and the exposure settings that had to be used in order to get any picture at all.  HDRP should be able to do that kind of thing maybe a little bit too accurately.  It can reproduce various physical camera artifacts at a very low cost as well..

I think the total difficulty is going to swing heavily depending on how hard they want to preserve prior artistic choices, and the willingness to lean into the new system to make different (potentially as good?) choices.

My heart goes out to the graphics engineers and artists who are working on this... time to start sacrificing some Kerbals to the Kraken

[K33N]

I don't want to just be negative, but why is this something to be excited about after 3+ years of dev and a disastrous launch? Won't this delay things again by more than a year?

[The Aziz]

What things? It's not like everything else halts until new rendering is finished. Most features should be unaffected by the development of the new system and the only obstacle really is some potential compatibility issues which should be resolved without ruining half of the code.

The implementation may take some time but there are things coming in parallel anyway. You know, can't way to see it, but I more can't wait to play it, and that'll be here sooner.

[JoeSchmuckatelli]

I don't know how relevant the comparison is, but the Satisfactory team just came out with a vid on their shift from Unreal 4 to Unreal 5.

Mostly about future proofing and giving the artists more tools and flexibility, the port took months not years. 

 

[Pat20999]

12 hours ago, K33N said:

I don't want to just be negative, but why is this something to be excited about after 3+ years of dev and a disastrous launch? Won't this delay things again by more than a year?

I disagree they should work on it but only in a fraction of the time till the 1.0 release, I want to have a good looking game if the game is fixed.

[Spicat]

Yes, I'm happy that this will bring some changes, especially to the lighting which is kinda bad in the current state (especially the white reflection which makes planets look like plastic):

[JoeSchmuckatelli]

7 hours ago, Spicat said:

especially the white reflection which makes planets look like plastic):

That shine works for Minmus, however. 

 

Hope they retain it's current look from space 

[Majorjim!]

On 6/2/2023 at 4:54 PM, Spicat said:

Yes, I'm happy that this will bring some changes, especially to the lighting which is kinda bad in the current state (especially the white reflection which makes planets look like plastic):

Agreed, the lighting in this game is not good. If you look at the KSC after dawn is horribly oversaturated.. it looks like it’s reflecting off snow… 

[FiendChain]

I'm excited for this revamp of the rendering system, which if implemented correctly should be a performance and quality uplift. That said I wonder what happened during development that caused the older PQS+ (procedural quad system) to degrade in performance so badly. 

https://youtu.be/NAVbI1HIzCE?t=970. In this video at the timestamp, Jason Booth who worked on improving PQS+ managed to get sub millisecond performance from it (shown in 24:40 in the video). Given this, is the game's poor performance actually the result of PQS's limitations or something else? It would seem premature to invest this much effort into revamping the renderer if it turns out to be an accidental regression. Personally I'm waiting for the physics system to be improved over KSP 1 before I decide to repurchase the game.

 

[Vanamonde]

Some comments removed. Keep it on-topic, please. 

[RayneCloud]

I've not kept an eye on this thread because I'm working on my own project at the moment in a different gaming market space. So, sorry for that.  I'm not sure if there's much for me to add really, or answer, at least from my personal experience and please remember that I do not work for IG/KSP 2 Team. (Though I wish I did, yes, even with things being a bit rough.) Anywho, let me know if there's anything else I can attempt to answer. (I'm not a subject matter expert as a note, just a former CM and QA lead with some experience and study behind me.)

[Spicat]

1 hour ago, RayneCloud said:

I've not kept an eye on this thread because I'm working on my own project at the moment in a different gaming market space. So, sorry for that.  I'm not sure if there's much for me to add really, or answer, at least from my personal experience and please remember that I do not work for IG/KSP 2 Team. (Though I wish I did, yes, even with things being a bit rough.) Anywho, let me know if there's anything else I can attempt to answer. (I'm not a subject matter expert as a note, just a former CM and QA lead with some experience and study behind me.)

Do you know if hdrp clouds can be used for ksp2 (which is not a game on a flat plane)? I’m wondering if they will improve clouds and if hdrp can help them

Edited June 8, 2023 by Spicat

[RayneCloud]

4 hours ago, Spicat said:

Do you know if hdrp clouds can be used for ksp2 (which is not a game on a flat plane)? I’m wondering if they will improve clouds and if hdrp can help them

I would imagine so, given what I know of the first version of PQS. Though, PQS in KSP 2 is a whole different beast. Just speculation though.