'Set light color' blueprint function produces incorrect color results

Development Rendering
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1

I think this is a bug but maybe not. Basically the “set light color” blueprint function will produce a different color result than a light that uses the same color for it’s base value.

Repro steps:

  1. place two point lights, light1 and light2. Be sure you can clearly see each light independently (they don’t visibly overlap etc).
  2. set the color of the lights (e.g. 0.5, 0.5,0). I used the color picker theme to store this value but I don’t think this detail is important
  3. in the level blueprint, using “set light color” set one of the light’s color to the same color value as step two.
  4. Play the level. Notice that while both lights should be the same color, they are not. I’m assuming the lights should look identical… but they don’t.
2

Hello ,

I was unable to reproduce this issue on our end. I have a few questions for you that will help narrow down what issue it is that you are experiencing.

Quick questions:

  1. Can you reproduce this issue in a clean project?
  2. If so, could you provide any additional steps that may have been left out of your original post?
  3. Could you provide screen shots of the lights in your scene so that I can see what it is that you are experiencing.
  4. Could you provide screen shots of any blueprints that may be involved?
  5. When setting the color for both lights could you bring up the color picker and copy and paste the hex code for the color you are using from one color picker to the next to insure that you are setting the lights to the same color?
3

Thanks for the quick reply.

  1. Yes. I repro’d in a new project

For the rest of the questions, here you go:
I don’t think there are any steps I left out but maybe the info below will help.

Screenshot of the editor (before playing the level)

61697-colorbug1.jpg
61697-colorbug1.jpg907×586 22.6 KB

Screenshot when playing the level (the lights on the left are those referenced in the blueprint)

61698-colorbug2.jpg
61698-colorbug2.jpg1143×573 27.1 KB

Screenshot of the only blueprint being used

61699-colorbug3.jpg
61699-colorbug3.jpg866×319 33.1 KB

Hex values are interesting. This is something that I only noticed after you requested this info. I’m using the color picker to store color values but it’s resulting in two different values.

Light object: 7F7FFF00

blueprint funtion: 7F7FFFFF

When I use the first number for both, the issue remains the same (the lights are different colors). When I try to input the second number into the light object value, it defaults back to the first value.

4

I was able to reproduce this issue on our end. I have written up a report (UE-21883) and I have submitted it to the developers for further consideration. I will provide updates with any pertinent information as it becomes available. Thank you for your time and information.

Make it a great day

5

This has been fixed in CL 2781330.
With 4.11 the color picker will now have separate fields for Hex Linear and Hex sRGB.