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Poster Wrong Reflections

I’m relatively new to 3d. I’ve recently made my own asset (a framed poster), bump mapped it and place it into UE4. Pic related is the fault: on the side, where the frame is facing away from the poster, it is reflecting the poster. Can someone please tell me how to stop this and make it reflect correctly? I think it’s something to do with the mesh and not the engine. Is it reversed normals or something? As I said, I’m new.

UE4 Mesh.png

Guys, please help with this. I can’t solve it on my own.

Don’t have a solution for you but I want to ask if you tested reversing the normals, as you mentioned?

Yes, sorry, I should’ve mentioned. Reversing the normals did nothing.

Can you see what I’m talking about? On the side of the black frame, like a giant tear?

This might be the UV issue, check your model uv, maybe UV for frame is stretched or has some issues.

Hi again. Sorry about the late reply. Yes, I have checked the UVs. The problem does not appear to occur in Maya when applying a texture to it. Here is a snapshot of the UVs:

7f816b03b52dc7e5fc6082982f4f03718657bff6.jpeg

Has nobody encountered anything like this before?

How does the lightmap UVs look like?
If you use the same as above, the padding might be a bit tight for the right island (top/bottom)

I don’t think it’s lightmaps or anything, just make sure your reflection probes are positioned correctly. If you’re using a normal map make sure you imported it with correct compression settings.

Just thought it might be worth a try. Sometimes I get exactly that kind of dark wedges if an island is not aligned with UV texels or has too slim padding…

Hi Aured,

There are a couple of things you can do here to get the best results for this. Unfortunately though, at certain viewing angles parts of the reflection are going to carry over.

You can alleviate this by adjusting the roughness in the material to not be so reflective or by adjusting the screen space reflections settings in the post process volume.

For my scene setup I’ve got a sky light, post process, and reflection sphere present.

For my material for the metal I’m using a constant1=0.1 for my roughness, constant1=1 for metal, and constant1=0.25 for base color.

Here is the default settings for all these and the result:

As you can see you can see the edge is similar to your post frame with the post reflecting on the side.

Poster_Default.PNG

In this next image I’ve adjust the post process screen space reflections intensity to 50 instead of 100.

Poster_Intensity.PNG

If adjusting the post process is unacceptable adjustment you can always tweak the roughness setting in the material.

Here I’ve adjusted it from 0.1 to 0.22 for a similar look that was achieved through the post process.

Poster_Material.PNG

With all that being said, this works really well in my case. There are some variables in all these that may need to be adjusted to fit your specific needs. By changing the roughness in the material and/or adjusting the screen space reflections settings you should be able to get some better results. :slight_smile:

Tim

@Tim Hobson

Thank you very much for that reply, it was very detailed. I shall give it a try very soon. As I would like the object to be highly reflective, I think I will set two materials: one on the glass so that the reflection is correct, and one on the frame with the roughness adjusted so that it does not show the incorrect reflections. Again thanks.

You should be able to achieve the same effect with one material and a mask fed into your material’s Roughness. This would be more flexible and somewhat cheaper to render when you have a lot of posters.

Also, while we’re on the subject, would anyone mind telling me why this is happening?

Sorry, I missed your reply. Could you quickly tell me how to do this? I know I keep asking to be spoonfed, but I’m at complete basic level with UE4, and I’m having trouble understanding certain parts of the material editor.

My guess is that this an artifact of screen space reflection, or an optimization performed on it. Despite all the shmancy new rendering features these days, game engine graphics are often still a bag of hacks and tricks. Sometimes the illusion breaks down, and this may be once such case you have to live with.

Try placing a reflection capture near the poster. I won’t guarantee that it will fix this particular problem entirely, but it can help fill in where screen space reflection breaks down.

Have you watched Introduction to Materials in UE4? If not, go do so!