Add unshaded mode to volumetric fog rendering

[jcarlosrc]

Describe the project you are working on

A non-realistic 3d game.

Describe the problem or limitation you are having in your project

I need to port a non realistic fog from Godot 3 to the new Godot 4 as in the picture. However, the current Godot 4 fog volumes only have albedo and emission properties. These can not be ajusted to obtain the required effect. While they are physically accurate, the nature of the game does require a different non realistic look. It could be solved adding more options to fog rendering such as the "unshaded" mode to render only its albedo color.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

Adding an unshaded render mode for fog volumes to achieve a non realistic look, similar to Godot 3. Maybe adding other options to have a more artistic freedom.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

render_mode unshaded should make fog to render only its albedo color with no light interaction.

If this enhancement will not be used often, can it be worked around with a few lines of script?

This is not a simple feature.

Is there a reason why this should be core and not an add-on in the asset library?

Fog was used extensively in Godot 3 and Godot 4 can not achieve the same look in some cases.

[Calinou]

This should already be possible. If you want fog to appear unshaded, set albedo to Color(0, 0, 0) (black) and set the emission color to the color you want to display instead. This will make fog not react to lighting in any way.

(This can also be done with BaseMaterial3D, in case you need features that are disabled when enabling the Unshaded flag.)

[jcarlosrc]

Setting Albedo= (0, 0, 0) and Emission = Color is not equivalent to an unshaded effect. First, emission creates a light that affect shaded objects. And also, the color result is similar but not actually equal. In the picture rendered with Godot 4 alpha, the "player" is affected by the emission color, and also the result is non uniform. I think fog volumes could have more options similar to BaseMaterial3D to obtain more precise results. Also, the density can not be controllerd with a curve which limits the desired effect.

[clayjohn]

If your goal is to achieve a simple fog similar to Godot 3, isn't using the non-volumetric fog sufficient? The benefit of volumetric fog is that it interacts realistically with lights while the non-volumetric fog does not

[jcarlosrc]

If your goal is to achieve a simple fog similar to Godot 3, isn't using the non-volumetric fog sufficient? The benefit of volumetric fog is that it interacts realistically with lights while the non-volumetric fog does not

Fog in Godot 4 does not allow the same level of control as Godot 3 for the non-volumetric fog. Thats why adding more rendering options could make Godot 4 fog to include gone options. The other way is getting back options from Godot 3.

[Calinou]

Fog in Godot 4 does not allow the same level of control as Godot 3 for the non-volumetric fog.

See #3429, #4619 and #2643.

[clayjohn]

I wonder if what you are really looking for is #4619 (bringing back some of the control that 3.x has) (Thank you Calinou for digging up the related proposals)

[jcarlosrc]

I wonder if what you are really looking for is #4619 (bringing back some of the control that 3.x has) (Thank you Calinou for digging up the related proposals)

I posted a request to bring back Godot 3 fog control features. However, with fog shaders coming in Godot 4, I believe they could bring more options for artistic freedom, not only for my specific case.