Playing around with ambient light color

[Diego]

Hola que tal!

I see very often ambient lights that are plain white. I know the role of ambient is just to eliminate the pitch black shadow, but I thought about doing some tests and see if changing the color helps in making the scene look more consistent, basically treating ambient like a faint radiosity, so I did

 

First test. Top image shows a yellow/orange light source with no ambient light. Middle image has a regular white ambient light. Bottom image has an ambient light with the same color as the main light source.

 

 

If there are more light sources this faint ambient should be a mix of colors. The top image shows only some blue glowing mushrooms and a faint blue ambient. Middle image I added some red glowing mushrooms, with more light I thought it needed more ambient but, more importantly, it's now purple. The bottom image shows a white ambient for comparison.

 

[Sotha]

Yep, ambient lights can give more to the scene.

 

In this shot, I've carefully balanced the real world color with the skybox. The setting sun color (light source) was taken from the skybox sunset and the ambient light color from the skybox sky. Both were darkened just a bit using the scientific method of gut feeling.

 

The color selection is very delicate.

It is not only about the color or the light source, but the overall color of the scene too: here the ambient comes from the SKY, not the light source. (Reflected light from the sky is the largest contribution to the overall ambient light.)

 

In addition, there is the gameplay effect: the ambient should still be dark enough so that the light gem is almost completely dark. In the shot above, shadow darkness makes LG almost dark, one notch above the complete darkness and crouch bonus makes the LG completely dark.

 

Then there is the challenge of ambient change when moving from scene to scene, which may look wrong if the ambients are a lot different from each other. This is important to remember!

 

I suppose one could use an infinite amount of time fine tuning the ambients.

 

Rule of thumb: take the largest and strongest light source into account. If the room is small with weak lighting wall/ceiling material starts to contribute as well. Avoid extravagant colors, use only slight effects. That way the transition from ambient location to another will be less jarring. If you really need a strong ambients, use a proxy location between the locations, so that the transition is softened.

[Obsttorte]

It's perfectly clear how high the impact of the ambient color is. Thanks for posting those images, as they point this out very clearly. I guess some basic rules are

• the ambient light color should fit the light colors of the light sources in the room, especially the brightest ones.
  
• brightness should be adjusted so that the player can see in the shadows but it is still believable that he is hidden in dark spots (remember you can adjust the lightgem behaviour)
  
• the saturation shouldn't be to high neither too low. it depends on the scene, too. less saturation makes the scene apeal more cold, what may be appropiate in outdoor areas, especially together with fog or rain effects. more saturation makes the scene look warmer, what is good in the inside of a manor for example.
  
• beneath the visual effect and the effect on gameplay one may consider what mood he wants to establish
  
• changes between locations should be smooth (this can also be affected by the light blending times)
  

Another note on the lightgem thingy: In my opinion it is not necessary that the player is completely hidden when in a dark spot. It really depends on the mission setup, and as the ai changes in 1.08 seem to take distance into account for visibility check IIRC, this could provide a way for a slightly different gameplay. The player cannot rely on shadows only, but must also use obstacles to stay hidden.

[Springheel]

• the saturation shouldn't be to high neither too low. it depends on the scene, too. less saturation makes the scene apeal more cold, what may be appropiate in outdoor areas, especially together with fog or rain effects. more saturation makes the scene look warmer, what is good in the inside of a manor for example.

Depends on the colour. A saturated blue light will look cold, a yellow or orange one will look warm. Coloured ambient lights are also good ways of unifying the colours of your palette...using a blue ambient outside not only looks like moonlight but also helps shift all the colours of your textures a bit towards blue, which helps unify the scene.

 

Another note on the lightgem thingy: In my opinion it is not necessary that the player is completely hidden when in a dark spot

 

Agreed. If it's bright moonlight out, there's no reason you should be invisible in shadows even at close range. By choosing brighter ambients mappers can affect the level of challenge in their level.

[someTaff]

There is some mighty screens, Diego!