Importing ies lights


#1

Hello,

is there a way to use ies lights?

Thanks


#2

If you are using the https://github.com/tobspr/RenderPipeline, yes, it supports IES lights.

Panda’s built-in light system does not natively support IES lights yet, so you’d need to write your own shader to handle them.


#3

That was quick, Thanks a lot I will check it out,
What I would like to make is a lighting analysis tool, where I can make a false colour render of the lux on the surfaces.

Sorry I have no experience with panda3d yet.

I would really appreciate your opinion about this.

I’ve attached a picture.

figure_l-qq-fc2

Thanks


#4

Interesting. Are the colours supposed to show the amount of light reflected from the surface or the amount of light incoming to the surface?

I think what you want to do is set up a HDR (preferably physically-based) lighting pipeline, and implement a custom tonemapping shader that translates the absolute luminance value resulting from this into a colour value. If you use the RenderPipeline, this may be easier as it already has a fairly advanced lighting pipeline with support for IES profiles and HDR, but this will depend on your specific requirements.


#5

It would be the incoming, would be the lux measured on the surface to be more specific, considering the diffuse light, so if for instance I have white walls the diffuse light is higher than a black wall and the room would be brighter and I would measure more lux.

I will try, but I guess it won’t be easy.

Thanks


#6

It will be hard to do this without learning shader programming, so I think picking up GLSL would be a boon in this effort.

If you just need to know the incoming light, and don’t need to simulate indirect bounces for now, it may get easier as you don’t need to think about materials. I would personally then start with a GLSL lighting shader (such as http://rdb.name/glsl-lighting.zip), adapt it to be able to accept an IES profile (which could be encoded in a texture), remove the surface normal-related calculations, and instead just map the incident light amount to a desired hue.


#7

Thanks a lot I really appreciate your help.

Unfortunately I need to make something really accurate at least as good as dialux in terms of lighting calculation. (Dialux is a free software which allows you to make lighting calculations)

I will let you know how it goes.

Thanks again