UE4 still does not have any proper way to do tinted glass

[Rawalanche]

Really? I don't see it on the "done for 4.24 list" but maybe you're referring to something else I'm missing. Would be really neat if true, especially if SSR takes it into account as well.

Ha! I knew I was not imagining it. Anisotropy indeed was there originally for 4.24 but then promptly removed. It seems to be back in 4.25!
https://trello.com/c/Qis6UrfU/534-an...ray-trace-beta

[Rawalanche]

It's just a screenshot, there can be 100 reasons for it. It's a default scene so all that the metal object has could be reflection capture captured before sphere were placed + SSR. I am 90% sure they'd show up in raytraced reflections.

[MostHost LA]

There is something pink in the left cornerl

Looks like the highlight seen through one of the sphere. They aren't perfectly aligned.

I just hope .25 isn't as bad of a mess as .24 has been.

[Suthriel]

Yes, yes yes yes yes yes yes!
https://trello.com/c/ADd56r3f/525-tr...y-improvements
Yes! Yes!

Yes yes yes yes!

Yes!
YES!

Looks good, but i still miss their reflections in the metal object (there is something pink in the left corner, but i am not sure, if it is one of the glass spheres, or one of its shadows on the ground), and in each other. So reflections for translucent/transparent objects seems still not active by default and have to be done by a customized engine, like:

https://forums.unrealengine.com/deve...in-ray-tracing

[Rawalanche]

Yes, yes yes yes yes yes yes!
https://trello.com/c/ADd56r3f/525-tr...y-improvements
Yes! Yes!

Yes yes yes yes!

Yes!
YES!

[BernhardRieder]

an update:

all my test results for creating a Glass Material using the Translucency Type Ray Tracing can be found here:
https://forums.unrealengine.com/deve...sue-how-to-fix

[BernhardRieder]

This is a very interesting topic. I am trying to work this out - step by step and I hope to get all your help. So here we go, please see the video below.

video: https://youtu.be/azGdQYGiq5g

Download UE4 Project File:
https://mega.nz/#!3g9QkAyI!z6VhQH_3x...KHMcQEHEPIaQEo


Thank you so much for any of your help, hints, tips & suggestions.

Happy pixeling,
Bernhard

[Rawalanche]

From what I understand, you want tinted glass to be rendered in a single pass, without resorting to using sceneTexture. To do tinted glass, you need to modulate the pixels behind the glass by a RGB value and add the reflected light/environment from the glass surface. There is no GPU blending mode that can do color modulation and color addition at the same time, therefore your request is impossible at the hardware level(*): you need to do it in two blend passes (first modulate, then additive).

(*) There are ways to do it on certain hardware: raytracing (RTX only) and tile-based mobile GPUs actually allow in-shader blending. There's also an optional feature on some shader model 5.1 GPUs that allows in-shader blending, at a cost.

So? I don't really care/mind about how many blend passes it takes. I mean for example Unreal already does one draw call per every material slot on a mesh. That's like saying it's impossible to have meshes with multiple materials on GPU because you can't do multiple materials in a single draw call. It may not need to be so efficient that it happens on the GPU shader level under the hood, that's not the priority here. Priority is just acceptable workflow from user experience standpoint.

[Deathrey]

There is no GPU blending mode that can do color modulation and color addition at the same time, therefore your request is impossible at the hardware level(*): you need to do it in two blend passes (first modulate, then additive).

https://docs.microsoft.com/en-us/win...color-blending

[Manoel.Neto]

From what I understand, you want tinted glass to be rendered in a single pass, without resorting to using sceneTexture. To do tinted glass, you need to modulate the pixels behind the glass by a RGB value and add the reflected light/environment from the glass surface. There is no GPU blending mode that can do color modulation and color addition at the same time, therefore your request is impossible at the hardware level(*): you need to do it in two blend passes (first modulate, then additive).

(*) There are ways to do it on certain hardware: raytracing (RTX only) and tile-based mobile GPUs actually allow in-shader blending. There's also an optional feature on some shader model 5.1 GPUs that allows in-shader blending, at a cost.

[amoser]

It seems you are far more concerned with the semantics of the posts in this thread rather than the substance of it. I am interested in the actual opposite. A few posts above, I've posted a video with the practical example of limitations of all the aforementioned approaches. While I may have failed to be precise in my formulations, I highly doubt most people would be unable to understand the general point I was trying to make.

Your posts seem to be intended to do anything except actually breaking down or solving the issue. I am far more interested in practical solutions to the issues illustrated by the video.

Nah, I was just trying to explain why I think that what you are asking for (or what I believed you were asking for) isn't quite as easy to implement or even necessarily as useful as you thought, and that you're likely to be disappointed if you expect it to be implemented soon as a native engine feature. I also explained in some detail how the other approaches you dismissed might actually be able to accomplish quite a few very specific things that you asked for and claimed were impossible.

Past that, maybe you're right, and most people other than me do understand what you're saying without difficulty, and I'm wrong for thinking you could have stated the problem more clearly. And maybe what you're asking for actually is something really easy to accomplish. At this point I'm clearly unable to find an adequate solution, whether that's because I'm misunderstanding what you're asking for, or for some other reason. It seems like I may not be alone, simply given that other people in the thread seem to be having similar difficulties, but I'd really be thrilled if someone comes along and implements a new shading model that solves all of your problems.

[Rawalanche]

Yes, and I quoted it verbatim.

And I don't doubt that you meant something closer to the following



None of that was actually present in your post at all, which is why I used it as an example of how you could add a bit of clarity to make sure people understand your intentions.



Again, this is what you wrote (emphasis mine):



You're saying that you actually meant something a bit different, which is perfectly fine. As I noted from the beginning, I wasn't certain what you actually meant.

But I still believe it serves as a good example of why it could be beneficial to spend a bit more time clarifying what you're asking in the first place, to make sure that what you write actually reflects how you want people to interpret it. If nothing else, it'll at least lessen the sense that you're deliberately antagonizing everyone who tries to actually answer your questions. I imagine most people don't like to take the time to respond to something, only to be insulted for not responding to something else different that wasn't actually stated or asked.

It seems you are far more concerned with the semantics of the posts in this thread rather than the substance of it. I am interested in the actual opposite. A few posts above, I've posted a video with the practical example of limitations of all the aforementioned approaches. While I may have failed to be precise in my formulations, I highly doubt most people would be unable to understand the general point I was trying to make.

Your posts seem to be intended to do anything except actually breaking down or solving the issue. I am far more interested in practical solutions to the issues illustrated by the video.

[amoser]

Did you actually read my post?

Yes, and I quoted it verbatim.

And I don't doubt that you meant something closer to the following

I precisely explained what I meant by complete shading model. Complete in terms of being able to cover all !basic! materials, not complete in terms of being able to simulate them to a degree offline renderers do.

None of that was actually present in your post at all, which is why I used it as an example of how you could add a bit of clarity to make sure people understand your intentions.

Here you are accusing me of not proof reading my posts and not making any sense while you clearly ignored a response to what you are currently calling out (again). So again, just so that you do not miss it. By a complete shading model I mean ability to at least to some degree create all the common real world materials - NOT ability to simulate them on the highest level possible (which would cover specific BRDFs for things like velvet). Basically something like VrayMTL, CoronaMTL or Blender's PrincipledBSDF, while they don't cover all the niche BRDFs/BSDFs, they do cover vast majority of basic real world materials.

Again, this is what you wrote (emphasis mine):

What I want is something that IS technically possible, to be a one click solution instead of complex set of steps. So that I, as an artist, can spend my time focusing on more important stuff. This just comes down to me being able to trust Unreal's shading model to handle all the possible real world materials. Currently it can handle all of them except tinted glass, which means it's incomplete. All I am requesting is that it's a complete shading model.

You're saying that you actually meant something a bit different, which is perfectly fine. As I noted from the beginning, I wasn't certain what you actually meant.

But I still believe it serves as a good example of why it could be beneficial to spend a bit more time clarifying what you're asking in the first place, to make sure that what you write actually reflects how you want people to interpret it. If nothing else, it'll at least lessen the sense that you're deliberately antagonizing everyone who tries to actually answer your questions. I imagine most people don't like to take the time to respond to something, only to be insulted for not responding to something else different that wasn't actually stated or asked.

[Rawalanche]

Ray Traced Translucency

Ray Traced Translucency (RTT) accurately represents glass and liquid materials with physically correct reflections, absorption, and refraction on transparent surfaces.
For additional information, see Ray Tracing Settings.

So a according to you, the example in the documentation with a translucent door that also has a dark tint is Impossible.
Hum... I wonder how the Unreal team went and did that... they may just be magic.

Care to show me the example you have in mind? Dark tint is easily possible, obviously, since all that's required is reduction of the opacity parameter. I am talking about colored tint. With saturated color such as green or red.

I've found identical formulation to one you've posted on this page: https://docs.unrealengine.com/en-US/...ing/index.html But I am failing to see any example of colored glass.

[MostHost LA]

Ray Traced Translucency

Ray Traced Translucency (RTT) accurately represents glass and liquid materials with physically correct reflections, absorption, and refraction on transparent surfaces.
For additional information, see Ray Tracing Settings.

So a according to you, the example in the documentation with a translucent door that also has a dark tint is Impossible.
Hum... I wonder how the Unreal team went and did that... they may just be magic.