Using textureLod in ShaderMaterial

hi guys,

I am new in BabylonJS, and trying to build some PBR materials with special effects, for example “thin film iridescence” in BabylonJS. I am learning something about PBR-Material and building my own PBR-Shader. I built a basic PBR-Shader, and now I want to do something more with IBL(image based lighting) and hdr. For Specular IBL i need to use textureLod Function from openGL to load mipmap according to the roughness levels. I tried something, but i always get the error “ERROR: 0:51: ‘textureLod’ : no matching overloaded function found”.

hier is what i tried.

in HTML file i added :

var engine = new BABYLON.Engine(canvas, false);
engine.getCaps().textureLOD = true;

In fragment shader i added

#extension GL_EXT_shader_texture_lod : enable

and in fragment shader i tried to use textureLod like this:

vec3 prefilteredColor = texture2DLodEXT(equirectangularMap, R,  roughness * MAX_REFLECTION_LOD);

then i got the error…“ERROR: 0:51: ‘textureLod’ : no matching overloaded function found”

I found some examples about textureLod and BabylonJS in playground, but non of them works.

Do you have any idea about this topic?



Hey! and welcome

Can you repro the issue on the playground? I should be able to fix it then

Hi Deltakosh,

here is the link:
It took me a little time to put everything in the playground, and i still could not put the dds file in the playground, which i want to textureLod.


hi use this

#extension GL_EXT_shader_texture_lod : enable
#extension GL_OES_standard_derivatives : enable

Hi nasimiasl,

It works!
I think “#extension GL_OES_standard_derivatives : enable” is what missed. With these two extension lines, i can use textureLod here. And what i actually want to try is this one "gvec4 textureLod ( gsampler3D sampler, vec3 P, float lod); ". Now the first step textureLod function works!!

thanks a lot for the help!

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Please share the final result with us!

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Hi Deltakosh,
here is the effect at first step i want to try, lod the dds reflectionMap according to the Roughness and MipMap.

and now i need to find a way to creat the dds file like the intern example DDS file, after that try to put this in my PBR-ShaderMaterial.


This is really cool!! I bet you gonna love the new feature I’m working on:

oh!! This is actually what i need!!! I will keep going on with this topic and keep trying!

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