Hi,
I’m trying to make the plane with a mirror substrate material with MH, but I have no luck using Lumen. I pushed the properties to high, but hair and eyes are not rendering correctly.
Unreal 5.8
Are there any special Cvars, or is it the limit of Lumen?
Pathtracer looks fine.
Hi @Bucz.co I’m sorry to see that you are running into this problem, sometimes technical problems can be frustrating. I’m going to be looking into this issue to see if we can find a solution. Could you please provide the following information, (I will be using it to try and replicate your project setting on my end to test and see what we can do) I will need:
So that I don’t leave you with just data gathering could you try this and see if anything changes (please make sure to back up your work in case anything breaks):
Hi, Thanks for your help.
I recorded a short video explaining my setup more. https://youtu.be/pn_3aTUaFKc
Hi @Bucz.co I’ve been researching the problem on my end and trying a few things, and I believe I have some news that may help you. Sadly I was not able to get clean reflections just using material settings and lighting settings, when I would get to a point where something would be fixed then something else would break hehe, I think this might be due to my hardware limitations or engine feature limitations. However, there is good news! I went ahead and started over with the new goal of getting clean reflection (or as clean as we can get it) while using a metahuman character. I simplified the mirror material as much as I could and began to use planar reflections. I will now share my process with you to see if this works on your end.
In the following instructions I’m assuming the following:
note:
If you need instructions in any of those please let me know and I’ll walk you thru them.
I started a new 3rd person project using Unreal Engine 5.8 and created a Metahuman that resembles yours. Placed it in the level and added a "simple shape (a cube) " to the scene to place the mirror material on it. I also place the assembled Metahuman blueprint in the level Infront of the mirror mesh.
Right click in your content browser (preferably in the folder where you would like to store your materials for your project) and select “Material”.
Let’s go ahead and name it and open the material editor
For the base color we will add a “Constant 3 Vector” and 3 Constant to assign them to the Metallic, Specular, Roughness:
Select the material node and in the details, panel type in “reflections” in the search bar → Make sure that “High Quality Reflections” and “Planar Reflections” are enabled. Go ahead and save, you can now close this window.
Let’s go ahead and apply the material to the mirror mesh
right now the reflection is not the best
We’ll go ahead and add a planar reflection to try and fix this. Let’s go to “Project Settings” and in the search bar type in “planar” → navigate to "Reflections → make sure that “Support global clip plane for Planar Reflections” is turned on and restart if prompted to.
Type in “Reflection Method” and make sure it is set to “Lumen”
Type in the search bar “Illumination” and set it to "Screen Space (Depricated)
Make sure to turn off “Motion Blur”
Let’s add a Planer Reflection to the scene and place slightly Infront of the mirror also scale it appropriately to the size of your mirror.
while having your Planar Volume selected lets go ahead and go to the Detail panel(mines is set up so that it appears to my left yours may be under or next to your outliner) and apply the following setting to your “Planar Reflection” Section as well as the “Advanced”. For step 5 you don’t need to use 500, that’s just the number that worked for me experiment with it sometimes 200 looks decent.
Please keep in mind that the reflection will not be 100% but it will get somewhat close.
One thing to keep in mind, is that this might break your reflective materials on your Metahumans, based on my research and looking thru the forums issues with lumen and reflections are a common thing. The only way that I was able to get around this was by bringing up the roughness of the problematic areas up as in parts that are close to 0 in roughness are the ones that will give you the most issues.
In the content browser I will go to where the face materials are and I’m opening “MI_Face_Skin_Baked_LOD0_VT”
In the search bar type in Post-Bake, and apply the following settings. This will make your metahuman skin look a bit matte but it will get rid of it the highly visual artifacts that we saw before.
I hope this helps, if you run into any issues applying these setting please let me know and I’ll see how I can help, best of luck with your project 
!
Hey,
Thank you for your dive deep research on this.
Planar reflection is an old method that mirrors geometry and works well only for flat surfaces.
I used to walk around this problem also by mirroring animation and making a transparent glass, but it also has some limitations in hair sims, etc.
Overall, I really was hoping that Substrate would make true actor reflection. It’s better than before, but still far away from the desired results. Maybe it’s the lumen, not material calculations.
Thank you!
