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How to define black paint in coating file

  • 7 October 2022
  • 3 replies
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Hi all,

in order to simulate lab results I would characterize a black paint (like as spray can) to replicate the result obtained on a prototype to which a layer of the aforementioned paint has been applied.

If I use coat I.05 or ABSORB the results do not seem to me to be comparable.

 

Thanks

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Best answer by Sandrine Auriol 10 October 2022, 11:35

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Hi Luca

In our examples, we model black paint by a MIRROR material and a coating I.95. It means that 5% of the light will be reflected. The rest will be absorbed.

Then to split these 5% between specular and scattered light, we set a Lambertian model with a scatter fraction of 0.8. That means that 5% x 0.8 = 4% will be scattered, so 1% will be in the specular. It is usually a good start but can be further improved. 

For example, Acktar shares some info on their website so that can give some ideas for a first model: https://acktar.com/product/lambertian-black/

Thank you very much Sandrine, your answer will surely help us both in this project and in future ones.

Hi Luca

In our examples, we model black paint by a MIRROR material and a coating I.95. It means that 5% of the light will be reflected. The rest will be absorbed.

Then to split these 5% between specular and scattered light, we set a Lambertian model with a scatter fraction of 0.8. That means that 5% x 0.8 = 4% will be scattered, so 1% will be in the specular. It is usually a good start but can be further improved. 

For example, Acktar shares some info on their website so that can give some ideas for a first model: https://acktar.com/product/lambertian-black/

Hi Sandrine,
did you have the opportunity to characterize the scatter also for a generic white paint?

 

Thanks a lot.

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