Static light vs. Dynamic light

shrike025

Hi,

I'm a bit confused about static and dynamic lights. Which one should I generally use in my scenes? I haven't find out much, only that dynamic lights affect performance more than static.

I haven't seen any performance issues on my PC, but I'm wondering if, for example, 8 dynamic lights in one room could cause some lags.

idiotamongus

It depends on the setting and the type of atmosphere you are trying to create. Certain light features are used for certain purposes. Unfortunately, I don't know what sort of thing you are trying to do so I can't help you any further.

angrysprite

Dynamic light is a true light source (and I think there is a limit of 5 or 7 or whatever that are visible to the player at any one time).

Dynamic light can change on-the-fly according to environment variables. One example might be a single dynamic light source causing the players shadow to actually move with them or dance around with the flames of a torch or something.


Static lights are fixed, the lighting doesn't change. No mater the perspective of the perspective of the player changing, etc. Think of them as being "burned into" the wall textures and such. So a quickie simplistic way to understand the difference is: Static light is dead - it's there, but it does;t move. Dynamic light is alive, lighting can change on-the-fly as the player moves and the environment changes.

Over-simplified explanation, but hopefully enough to help OP understand them.

Oh and one more thing: Dynamic lighting takes more computer processing horsepower than static lights do (which is why the game client will limit the number the player can see; even if you place twenty in a room the player will only see five (or whatever the limit is, I forget)).

shrike025

Ok I think I understand now how it works .

A player won't recieve any shadows from a static light, correct?

That horsepower is what concerns me most. Are you using mainly static lights and put dynamic only when it's necessary, or two, three dynamic light in every room won't be big of an issue?

angrysprite

shrike025 wrote: »

Ok I think I understand now how it works .

A player won't recieve any shadows from a static light, correct?

That horsepower is what concerns me most. Are you using mainly static lights and put dynamic only when it's necessary, or two, three dynamic light in every room won't be big of an issue?

I don't usually pay attention to dynamic versus static lights, I just plop stuff I need. However, if I wanted a really specific look and needed the light to help with that specific look I may then look for dynamic lights directly. But yes, player shadows are a perfect example of what the difference is.

Occlusion is the 3D wire mesh and rendering of areas and textures the player cannot see. So I will use this crazy example:

Let's say you've recreated Prtoector's Enclave from scratch. Bad place to use a lot of local dynamic lighting throughout because large chunks of the city can be seen all at once. This also is why PE is a little lagger than other zones in the game. And FYI: Cryptic does use a "Global" Dynamic light source in PE - we don;t get global light sources in Foundry unless it's built into the map).

Local light source: for example a torch or campfire. Light is always coming from the direction of the source.
Global light source: (cannot be seen by the player) - like the Sun or Moon - too far away so all that light is coming from the same direction (usually high in the sky).
Static light source: can be global or local, but no dynamic shadows (moving shadows).

Anyway, if the player can see a lot like in PE it can slow down the computer (horsepower is needed to draw all that stuff). However, if you go into the Moonstone Mask for example: there you can only see parts of it at a time: the main floor, but not the little alcoves and so on. So here you can use dynamic lighting more effectively.

So if I have a three room house, I can put five lights in each room without problem as long as I cannot see all 15 at the same time. If I see five in the first room, then look through the door and see two from the other room and only three from this room I'm okay. So the dynamic lighting limits rule (and shaders rule and mesh rule and all that stuff in 3D Modeling) apply to what the player sees on their screen at any one time.

If you have 100 lights in a room, it's okay if the player only sees five at a time (or whatever the limit really is - it might be higher, like 10 or 15, I forget). I hope this helps.

shrike025

Thanks a lot for your detailed answer, this will help me a lot .