I have a static mesh that has an emissive material applied to part of the mesh. The emissive material successfully cast light to surrounding objects. However, the face of the mesh with the emissive material fails to cast light on the rest of the mesh.

This is how the unlit scene look: enter image description here

The parts circled blue has the emissive material, and the sphere and cube are both lit by the emissive material. However, the part of the stairs (highlighted in red) does not get lit.

The lit scene: enter image description here

Is there a way for the stairs to be lit by itself?


from the UE4 docs on Emissive lighting there are a couple of things that may not have been done. These would be to have the Stairs set to be lit by emissive lighting and the Emissive Strength is not strong enough to reach the steps of the stairs. So:

  1. Check to True that the Stairs receive emissive lighting.
  2. Add a property to your Material that will multiply the emissive color by a value called Emissive Strength. This will increase the influence of the emissive light.
  • \$\begingroup\$ 1) that was the first logical thing to do, which I obviously did. 2) As you can clearly see, the sphere is well lit by emissive which means the strength is enough. \$\endgroup\$
    – Alchemist
    Jan 11 '17 at 4:39
  • \$\begingroup\$ If you do not provide any additional details or screen shots of graphs / code samples there is no way of knowing what has been done. Secondly, due to the lighting and shading it seems that the sphere is between, or in the middle of all the other objects. Is the sphere above the curved stair case? What does your material graph look like? What is your lightmap resolution on the mesh? What do your UVs look like for the stairs? What is the distance from the Emissive material to the sphere, to the end of the stair case? Did you try increasing emissive strength? \$\endgroup\$ Jan 11 '17 at 15:11

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