LWRP poor / broken specular highlights on Android with large objects

I am finding that Specular Highlights disappear on large objects with LWRP Lit materials on Android. They also seem to be low quaility when they do appear.

For example, take a default cube and add a LWRP Lit material to it, set to Specular workflow and a smoothness of 0.8. All looks fine in the editor but the specular highlight is not smooth when deployed to Android. Then if the cube is scaled up, it remains fine in the editor, but the lighting breaks on Android when the scale exceeds 160 or so.

This is the editor view of a red cube with a LWRP > Lit red / specular material and a directional light pointing inline with the camera.



Below is the same view on a Galaxy S8 G950. The quality setting is "high" and the render pipeline asset is the high quality one from the LWRP template project. Although the view below has the cube scale set to 150, it looks the same with the scale set to 1. Note the poor quaility of the highlight.



But worse, as the scale of the cube increases, the spec lighting fails and the red of the cube turns white. Below is the same framing as above, just with the cube scale set to 166.



Eventually as the scale of the object increases, the red material is lost altogether.



Anyone know what's going on and how to fix it so that Specular highlights don't go wierd / disappear with large objects? Is this a setting with the render pipeline I haven't yet discovered?

Thanks

DC

 

Yes - if you think it could be a bug. I wanted to make sure I wasn't being a total idiot before wasting the Dev's time
DC

 

More looks like a precision issue.

 

This looks like it might could be related to problems I've been having with specular highlights on mobile (both Android and iOS) with shader graph materials on LWRP
https://forum.unity.com/threads/lwr...-specular-problems-on-ios-and-android.700688/

In my case I found the problems got worse with smaller camera FOV angles as well, but if you have problems with simple scaling it sounds like there could be something in the specular calculations that is locked to a specific size and camera setup, rather than being relative to the scale and FOV of the current scene?

 

@lostminds - your issue does seem to exhibit the same problems I described here. It has been filed as a possible bug under case 1164822 so no doubt will be dealt with in due course

DC

 

@davidcox let's hope so, I've also filed a bug about this, I think back in 2018, and I haven't heard anything since then. I'm thinking this is likely a bug in the light weight render pipeline or shader graph, and I'm not sure how the development of those packages is related to the main Unity editor development cycles or what the roadmaps are for them. I haven't seen any updates for a while on the light weight render pipeline or shader graph so hopefully one will be due soon.

 

Just a small update in case anyone is still following this (like I am). It seems like the bug will be fixed in Shader Graph 7.1.1 part of the new Universal Render Pipeline (previously called Lightweight Render Pipeline). I don't know when this will be released, but it looks like it will require Unity 2019.3.

The current beta Unity 2019.3.0b3 has Shader graph 7.0.1, which seems to improve/fix the precision/artifacts but the highlights are still exaggerated when it comes to brightness on mobile in my tests.