TDM Fresnel Mod

[nbohr1more]

Howdy!

 

 

With recent discussions around shader design and rim \ fresnel, I decided to try adding this effect back to the 2.09 ambient.

tdm_base01.pk4

(Bug fixed. You can now have bloom enabled!

Recommended setting: r_postprocess_colorCurveBias to 0.35

Installation:

Rename your tdm_base01.pk4 in your darkmod directory and copy this into that directory.

[Filizitas]

It looks great, i mean the screenshots are too small to actually see something.

But the idea looks good.

Can you make a video at max graphics settings?

[nbohr1more]

Hmm...

For some reason the moddb preview screens no longer click-through to the full size ones. (These ones do)

 

 

I'll make a video tonight.

[nbohr1more]

Moar!

 

 

[Filizitas]

That looks really hot yes, ship this!

[Hooded Lantern]

Thx. Does this work with totallytubulars shaders?

[nbohr1more]

23 minutes ago, Hooded Lantern said:

Thx. Does this work with totallytubulars shaders?

No, it is an alternate design. I guess I should credit Duzenko since I piggy-backed off his "ambientRimColor" design.

 

totallytubular has some interesting design ideas but it will take some work to port them in a way that doesn't break standard light projections...

[nbohr1more]

And more!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[wesp5]

So can somebody do some comparison sceenshots or explain what's special about this new method?

[nbohr1more]

7 hours ago, wesp5 said:

So can somebody do some comparison sceenshots or explain what's special about this new method?

Fresnel makes surfaces brighter a glancing angles. It make normal maps more visible in ambient only lighting and gives more depth similar to SSAO.

Here is Caduceus of St Alban with no Fresnel

 

Here is the Fresnel Mod:

 

[peter_spy]

First off, for before/after comparisons, something like https://imgsli.com is your friend

Secondly, fresnel effect is a phenomenon occurring mostly on highly reflective surfaces, so having that on materials that don't even use speculars doesn't make much sense to me.

[nbohr1more]

13 minutes ago, peter_spy said:

First off, for before/after comparisons, something like https://imgsli.com is your friend

Secondly, fresnel effect is a phenomenon occurring mostly on highly reflective surfaces, so having that on materials that don't even use speculars doesn't make much sense to me.

See: http://filmicworlds.com/blog/everything-has-fresnel/

All surfaces have some fresnel response.

That said, my mod scales fresnel response with specular amount.

[wesp5]

9 minutes ago, nbohr1more said:

That said, my mod scales fresnel response with specular amount.

So could this be added as an option to the core mod? Like better graphics costing fps performance?

[nbohr1more]

9 minutes ago, wesp5 said:

So could this be added as an option to the core mod? Like better graphics costing fps performance?

So here is the full story as I can tell:

1) TDM from "Thief's Den demo to TDM 1.02" had no Fresnel in the ambient

2) TDM 1.03 had Fresnel in the ambient thanks to JC Denton's "HDR-Light" shaders

3) This was the status quo until TDM 2.06 where Duzenko converted the shaders to GLSL and the Fresnel component was omitted

Duzenko was not sure about some of the design ideas in the old ambient so he only implemented what he understood was "physically correct"

4) Duzenko then began discussing rim lighting which uses roughly the same math as fresnel

5) I tried the ambientRimLight option Duzenko created on the mission "Inn Business" and found that it was not quite right \ did not approximate the 1.03 to 2.05 look

6) I experimented with adding modified rim lighting to all ambient lighting

7) Duzenko helped fix this design by indicating that the fresnel needs to be modulated with light projection

I spent hours tweaking until I found that modulating the fresnel with diffuse helped get the right look and now it is "close" to 1.03

The plan for the future is to possibly go with a proper PBR model so Fresnel as done here may be obsolete at some point.

[cabalistic]

6 minutes ago, nbohr1more said:

The plan for the future is to possibly go with a proper PBR model so Fresnel as done here may be obsolete at some point.

I really need to stress this, but no, that's not "the plan" The plan is to do some experiments with PBR some time in the future after some other groundwork has been finished, and from that figure out what might or might not be done, and how. Even if the outcome is generally positive, that will almost certainly not happen for the next few releases, and even then it could realistically only apply to newly created missions with PBR in mind. So the current lighting is not going away in the foreseeable future (and beyond).

[nbohr1more]

My "plan" was to offer a "legacy mode" for missions that are heavily reliant on the old 1.03 to 2.05 look.

If my changes are "good enough" (tm) or someone is incline to improve on them and add them to the core, then no "legacy mode" would be needed.

Since PBR already requires fresnel a proper design (rather than my hack) would partially complete this objective.

So we have a few options:

1) Leave my work as a fun mod that people can add if they want

2) Incorporate my work as a cvar toggle \ legacy mode

3) Incorporate my work as part of the core mod and redesign it to be "proper"

If we go with options 2 or 3, I can also create a cvar for "fresnel strength" so players can tune it to taste.

[peter_spy]

1 hour ago, nbohr1more said:

All surfaces have some fresnel response.

"Some" is the keyword here, you added so much fresnel to those stone statues they look like glossy surfaces, and they don't even seem to have a specular map or specular + cubemap combo. IMO there's no point in testing that on materials that are diffuse + normalmap only, if you want to have even slightly meaningful results (as relatively meaningful they can be for the non-pbr world, so to speak). It's "everything is shiny" first, then "everything has some fresnel response" as a consequence.

Edited March 13, 2021 by peter_spy

[nbohr1more]

41 minutes ago, peter_spy said:

"Some" is the keyword here, you added so much fresnel to those stone statues they look like glossy surfaces, and they don't even seem to have a specular map or specular + cubemap combo. IMO there's no point in testing that on materials that are diffuse + normalmap only, if you want to have even slightly meaningful results (as relatively meaningful they can be for the non-pbr world, so to speak). It's "everything is shiny" first, then "everything has some fresnel response" as a consequence.

Did you try the mod?

The screens were taken with the gamma a little high but in motion this does not look glossy.

It was a tough balancing act to get the correct response at normal map scales and at macro scales ( building features ) but I will admit it is a little stronger than 1.03 at this point.

I can probably ditch the higher exponent "edge highlight" specular function and just apply a small amount of specular modulation to the lower exponent part.

This was just the first version I was happy enough with to offer publicly as a toy.

[peter_spy]

14 minutes ago, nbohr1more said:

Did you try the mod?

The screens were taken with the gamma a little high but in motion this does not look glossy.

Not yet as I'm still on 2.08, but that amount of fresnel on the statues would suggest they're highly reflective, so if they're not glossy, they just look wrong. That said, the static screens look rather random. The last example with the comparison looks kinda like fake GI or ambient light bounces. But I suspect it will look completely broken in my environment, where every surface actually does use a specularmap, and sometimes specular + cubemap. Would have to install 2.09 to be sure.

[ate0ate]

Wow, this is really a nice change. I'm obviously rather new here so I would expect my opinion to hold little weight, but I felt compelled to say how much this improves the illusion of depth especially in darker areas. I particularly like the look of some outdoor areas. Some maps are a bit unnaturally dark for a full moon bright starry night, which is never pitch black in reality. This really makes things look much better to my eye. Thanks for this! Playing through Penny Dreadful 3 was a joy.

[nbohr1more]

Thanks for the kudos!

I think I have figured out the black boxes. The fresnel equation allows negative numbers...

[nbohr1more]

See the first post for a new build. You can now enable bloom with no artifacts.

[lowenz]

Will try!

[lowenz]

2.09: https://i.postimg.cc/02Y5VBjD/0.jpg
 

2.09 with fresnel: https://i.postimg.cc/fbrM34qn/1.jpg

 

Rim light "fights" vs SSAO along the 3D models borders so the result is.....strange.

Look at the pipe.

 

(please enlarge the images in 2 different browser tabs)

Edited March 14, 2021 by lowenz

[nbohr1more]

Yeah, the conflict is to be somewhat expected since both are doing naive view based approximations .

I can try another (reduced) SSAO multiply pass to make it less weird.