Material looks metallic and pretty smooth/shiny surface with GLES2 on Android

[volzhs]

Godot version: 3.2.2 df87601c88

OS/device including version: Linux mint 19.3 / Galaxy s8+

Issue description: Material looks metallic and pretty smooth with GLES2 on Android.

This is how it looks on desktop

This is how it looks on Android it looks pretty metallic and smooth/shiny surface. too shiny on front side, and too dark bottom of the sphere.

Steps to reproduce:

1. Download attached sample project
2. run on PC and Android

Minimal reproduction project: mat_test.zip

[clayjohn]

I think this is connected to #34257

[volzhs]

after further testing, this issue happens with PanoramaSky or ProcedualSky. without it, it looks same with PC and mobile on GLES2.

here's another recording with PanoramaSky.

Linux mint 19.3

Galaxy S8+

[clayjohn]

I think what is happening is that the objects are not reading from the blurred mipmaps of the environment on Android. So it is as if they always have a roughness of 0. But even worse, we use the the radiance map to approximate diffuse irradiance, so it is read from twice at the lowest mip level, resulting in extreme shininess.

[NeoSpark314]

I briefly investigated this issue some time ago here: https://github.com/godotengine/godot/issues/33633#issuecomment-554537340 and it looked like there is an error in the roughness mip map computation on android for the sky and mip-level 1 is black while all other mip levels (0, 2, 3, ...) look correct.

[wombatwingdings]

I have this problem too. Phone is Motorola G6 Play (GPU: Adreno 505).

[clktmr]

I did some investigation on this and basically @clayjohn assumption is correct. Because GL_EXT_shader_texture_lod is not supported on most Android devices (including Oculus Quest 2), both blurring and reading from radiance/reflection fails. My current workaround is to reduce sky/reflection contribution to ambient lighting.

Maybe it would be worthwhile to think about a possibility to bake reflection maps. This would also improve rendering of roughness, which currently only reduces intensity of the reflection. This would however add an additional one for each cube map to the scene shader, because we need a specific one for roughness and the most blurred one for ambient lighting.

[wombatwingdings]

Does anyone know if it's easy to force a roughness value of 1 everywhere instead of computing it and getting it wrong to get round this issue? Having shiny materials everywhere looks horrible. But I would think having rough materials would look OK for most games (including mine). I'm not suggesting committing this to the repo, but would be a useful workaround for those building from source. Thanks!

[Calinou]

Does anyone know if it's easy to force a roughness value of 1 everywhere instead of computing it and getting it wrong to get round this issue? Having shiny materials everywhere looks horrible. But I would think having rough materials would look OK for most games (including mine). I'm not suggesting committing this to the repo, but would be a useful workaround for those building from source. Thanks!

If you can recompile Android export templates, you can clone the 3.4-stable tag and make the following change in scene/resources/material.cpp:

diff --git a/scene/resources/material.cpp b/scene/resources/material.cpp
index 0af0378c83..51303b39a6 100644
--- a/scene/resources/material.cpp
+++ b/scene/resources/material.cpp
@@ -825,9 +825,9 @@ void SpatialMaterial::_update_shader() {
        } else {
            code += "\tfloat roughness_tex = dot(texture(texture_roughness,base_uv),roughness_texture_channel);\n";
        }
-       code += "\tROUGHNESS = roughness_tex * roughness;\n";
+       code += "\tROUGHNESS = 1.0;\n";
    } else {
-       code += "\tROUGHNESS = roughness;\n";
+       code += "\tROUGHNESS = 1.0;\n";
    }

    code += "\tSPECULAR = specular;\n";

This will only affect SpatialMaterial, not custom shaders. You could edit drivers/gles3/scene.glsl and drivers/gles2/scene.glsl to affect custom shaders as well, but it's a bit more involved.

[Acvarium]

Updated my project for Oculus Quest to Godot 3.4 and than to 3.4.1. Secular glitch is showing up with directional light, if secular value for material is not 0

https://user-images.githubusercontent.com/463177/143664649-6cfe3ed2-8203-494d-9d80-26465298ff3c.mp4

[Acvarium]

Tested today with Godot 3.3.3. No sparkly issue there. That is only with 3.4 and 3.4.1 with GLES2 rendered

[Calinou]

Tested today with Godot 3.3.3. No sparkly issue there. That is only with 3.4 and 3.4.1 with GLES2 rendered

Please open a new issue with a minimal reproduction project attached.