How do you make some parts of a material more emissive?

Article Details

Poster: Morten
Article ID: 751
Posted: Fri 05 Feb 2016
Approved: Yes

How do you make some parts of a material more emissive than others?

You will need a special Color Map texture with a mask channel in order to make parts of a Standard material more emissive than others.

A Color Map texture normally has 3 channels: red, green and blue.

In addition to the red, green and blue channel, you can add a socalled alpha channel to the texture if you've got Adobe Photoshop, GIMP or a similar image editor.

The alpha channel can be used for 3 different purposes in Lumion:
  • Color Map Alpha clips object (For making parts of a material transparent)
  • Color Map Alpha masks Reflectivity (For making parts of a material more or less reflective)
  • Color Map Alpha masks Emissiveness (For making parts of a material more or less emissive)
In this article we will focus on the third option, i.e. making parts of a material more emissive.


1) If you're using Adobe Photoshop, please click here to see how to add an alpha channel.

2) When you paint the alpha channel, bear in mind that black won't be emissive at all in Lumion and white will be fully emissive. Greyscale tones inbetween those extremes are more or less emissive depending on how close they are to pure black and pure white.

3) Once you've happy with your Emissive mask, please click here to see how to save the Color Map texture as a 32-bit texture in TGA, BMP or TIFF format.

4) Then open Lumion and add a Standard material to the object in Lumion.

5) Assign your Color Map texture with the alpha channel to the Color Map slot in the Standard material.

6. If the full settings are not shown, then click on the Show Extended Settings button :

7. Click on the Settings Tab and then the third Texture Alpha button:

8. Adjust the Emissive slider as desired.

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