LOD popping and lightmap resolution flickering


As the title says, I’m having some really serious issues regarding a scene I’m building in Unreal 4.9.

I’ve been using some transparent planes to create graffiti decals, as I’m doing a night scene and I’ve ran into the issue of decals not being illuminated by indirect lighting (there’s a million threads on it already it seems) so I was using planes with a trim texture of graffiti.

I have a video but it’s too large to upload, but here is a quick collection of screenshots regarding the problem. You can see between each screenshot that the lighting changes. The LODs pop on transparent materials also, and I think that is a related issue.

In terms of what I’ve done before this problem manifested, I was creating a Transparent Masked material for the graffiti. I noticed the LODs popping on this material, but was unsure if it was related to having the material editor on a second monitor.

Hi jakebelgian -

Deferred Dbuffer Decals can be light by indirect lighting. They are not on by default, but you can turn them on via the Project Settings and enable the following:

After setting them, you will need to restart the project to make sure that they are enabled.

Once that is done you can use the following Decal Types to have them be lit by Indirect Lighting:

When applied to the level with default settings on your light you can achieve a look like this one:

With a little adjustments to the Light Source Intensity and Color as well as increase the Indirect Lighting Intensity OR leaving the Indirect Light Intensity on the light the same and adjust the Indirect Lighting Intensity in the Global Post Process Volume:

I have attached a very small sample project demonstrating my setup. Hopefully this will allow you to not have to use the errant planes from your post. However, I would like to see if I can identify that problem as well, but your pictures do not have built lighting and I need to be able to see the effects of having completed your lighting build in order to see an accurate reproduction.

Thank You

Eric Ketchum

[Test Project 4.9.2][5]

Hi, thanks so much for the response, that’s fixed the decal issue.

I also figured out what was causing the popping effect, and it appeared to be that I was out of texture streaming memory! I didn’t have a warning in 4.9 but I ported the project over to 4.10 and the message appeared right away.

Do you have any suggestions as to what a safe number might be to increase the texture streaming pool to?

Thanks again,