Blur silhouette of mesh with material or post processing??

Development Rendering
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1

I am attempting to create a material or pp material that will effectively blur the silhouette of a mesh. I need to be able to detect edges and then blur inward. I would use this mask as an alpha to blend between postprocessing0 and the mesh render itself.

I know that I can create an outline with a pp material and flag meshes I want to inherit the outline as “render custom depth.” But how would I then blur inwards?

Here is an example:

89710-example.jpg
89710-example.jpg1000×1000 48.7 KB

So I need a way to render this mask somehow… either within a material… or a pp material.

89711-mask+.jpg
89711-mask+.jpg1000×1000 33 KB

I would then use this mask to create a translucency mask that would effectively blur the silhouette.

2

Here is the post process material:

89753-clipboard+image+(17).png
89753-clipboard+image+(17).png3347×987 824 KB

A bit involved but not as expensive as I expected.

2 Likes
3

This is how it looks like:

89754-clipboard+image+(18).png
89754-clipboard+image+(18).png1078×427 395 KB

1 Like
4

This is fantastic. This is very much so what I was thinking. I will implement this asap. Thank you very much for helping me expedite this! I will let you know how it goes!

5

If you found an answer helpful then please mark it as accepted. :slight_smile:

6

i guess the result of the last division on the right must be connected to the emissive color in the PP material right?it doesn’t seem to work in UE5 btw, anyone managed to make it work?

7

Thanks a lot for your answer, I’m currently having the same issue. Question - this node that you marked as “tweak to match aspect ratio”, is that a constant3vector node? I was following your node structure, and because of this particular nod I’m having errors. Thank you!

8

Hello, has anyone gotten this to work in UE5?

9

The aspect ratio is a vector 2, on the image it has the value of (1, 1.6). It should be matching the screen aspect ratio to make the blur steps even on both screen axes.

10

The technique should work in UE5. What seems to be the problem?

11

I managed to get this working in UE5 after I asked the question. I couldn’t get it to work in the Quest3 headset though.

12

Yeah, standalone headsets are very limited. :\

13

Did you modify something to get it working in UE5?

14

Hi ZoltanE thx for the material!I managed to make it work and it does look awesome indeed. Only problem is that when the PP material is enabled, it has noticeable impact on the whole scene (especially lights). I would expect it to only affect actors with Render CustomDepth Pass enabled, did I do something wrong or is this a drawback of this technique?

15

Hm, I’m not sure what could be going on… Could you post a few images to show the issue? Something like a before/after comparison.