LIGHTS LIGHTS LIGHTS!

[Lahnius Zaks]

OK so am I alone in an odd land where teleporting to a location that has alot of lights does not illuminate light fixtures unless your camera view actually sees that light fixture?

Our place utilizes lights quite a bit, but the problem we're seeing, and hearing about, is that the lights do not shine unless their actually looked at ... oh and this also falls into lights not going off when shut off unless you look at them again ...

A few updates back this was not a problem, but it seems to be now.

[Ohjiro Watanabe]

Go to Preferences/Graphics and make sure that Advanced Lighting Model is turned on.

[Dresden Ceriano]

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Lahnius Zaks wrote:

OK so am I alone in an odd land where teleporting to a location that has alot of lights does not illuminate light fixtures unless your camera view actually sees that light fixture?

Our place utilizes lights quite a bit, but the problem we're seeing, and hearing about, is that the lights do not shine unless their actually looked at ... oh and this also falls into lights not going off when shut off unless you look at them again ...

A few updates back this was not a problem, but it seems to be now.

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Um... is this one of those philosophical thought experiments?  You know, like, "If a light turns on and no one is there to see it, does it cast any light?"

...Dres

[Nova Convair]

If advanced lighting is off the number of lights that are rendered is limited. Oh - and in case you have left the facelights visible or even wear one - this ones count too.

So if you have 20 lights in view only a few of them will show. If you zoom in on one this one will be promoted and will start to shine. Another one - further away - will be switched off then of course.

So switch on advanced lighting, set the view range high enough that all fits in what you want to see. I guess a specific graphics quality is required too.

[Phil Deakins]

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Dresden Ceriano wrote:

Um... is this one of those philosophical thought experiments?  You know, like, "If a light turns on and no one is there to see it, does it cast any light?"

...Dres

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It depends on what you call light. If a light is turned on, it emits photons, whether or not anyone is there to see them, but photons aren't what we think of as light. What we think of as light only occurs when photons hit the retina and are interpreted by the brain. If photons were light, then the whole of space would be lit up because it's full of photons.from stars.

It's the same with a tree falling a forest. The air is moved by the event but the air movement doesn't become what we think of as sound until it hits and vibrates the ear drum. So no 'sound' is generated by the falling tree whether or not ahyone is around to hear it. Air movement is generated, of course, but it only becomes what we think of as sound when it hits the ear drum.

[Ohjiro Watanabe]

That's the same as saying a chair isn't there unless you sit on it.

A rainbow on the other hand, that's a different kettle of fish.

[Phil Deakins]

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Ohjiro Watanabe wrote:

That's the same as saying a chair isn't there unless you sit on it.

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No it's not. A chair is a chair whether or not someone sits on it.

Light and sound are usually thought of (preceived) as being something they are not. neither light nor sound, the way we think of them, occur outside the body, although we think of them as being outside the body.

[Qie Niangao]

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Lahnius Zaks wrote:

A few updates back this was not a problem, but it seems to be now.

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Hmm. If this is what I think it is, it must have been quite a few updates ago because I think it's a function of the more conservative interest list that speeds up rezzing everything else by more aggressively "forgetting" stuff that's no longer in view.

In fact, this effect is even more relevant to projected lights under the Advanced Lighting Model than to those old-school, spew-light-in-all-directions point-source lights that permit only a few (six?) emitters. Those old lights are pretty bizarre, with the "six nearest lights in a scene" determined by proximity to the avatar, not the camera.

Projected lights are weird, too, and depend on the light emitter being visible. In fact, you can completely defeat a projected light by covering it in a hollow sphere that's opaque on the outside, even when that inner hollow surface is transparent. If the source is completely hidden, its light is hidden too.

[arton Rotaru]

Sounds like this:

https://jira.secondlife.com/browse/BUG-7084

[Bobbie Faulds]

 

• Viewers that do not have advanced lighting enabled can only render 6 lights at a time and projectors will be rendered as omnidirectional light sources. (OpenGL limitations allow for 8 light sources, SL appears to reserve one each for the Sun and Moon.)
  • Viewers that do have advanced lighting enabled can render as many lights as their graphics card allows; it is not hard-limited by the viewer.
• Lights with a high intensity have a wash-out effect when overlapping. Keep this in mind when using multiple lights. Never create an abundance of lights to get around the 6 light maximum in basic lighting, as viewers with advanced lighting will be washed out and may suffer from client lag.

From the SL Wiki.

 

[Lahnius Zaks]

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arton Rotaru wrote:

Sounds like this:

https://jira.secondlife.com/browse/BUG-7084

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Thank you, this is very close to what the problem is ... from what I have read, it does seem to be the nature of the problem.

[Vulpinus]

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Qie Niangao wrote:

Projected lights are weird, too, and depend on the light emitter being visible. In fact, you can completely defeat a projected light by covering it in a hollow sphere that's opaque on the outside, even when that inner hollow surface is transparent. If the source is completely hidden, its light is hidden too.

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Thank you for that - it explains why my lights seem to flicker sometimes when I move about, and never seem to do what I expected unless I'm stood in the room with them.

[Qwalyphi Korpov]

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Qie Niangao wrote:

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Lahnius Zaks wrote:

A few updates back this was not a problem, but it seems to be now.

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Hmm. If this is what I think it is, it must have been

quite a few

updates ago because I think it's a function of the more conservative interest list that speeds up rezzing everything else by more aggressively "forgetting" stuff that's no longer in view.

In fact, this effect is even 

more

relevant to projected lights under the Advanced Lighting Model than to those old-school, spew-light-in-all-directions point-source lights that permit only a few (six?) emitters. Those old lights are pretty bizarre, with the "six nearest lights in a scene" determined by proximity to the avatar, not the camera.

Projected lights are weird, too, and depend on the light emitter being visible. In fact, you can completely defeat a projected light by covering it in a hollow sphere that's opaque on the outside, even when that inner hollow surface is transparent. If the source is completely hidden, its light is hidden too.

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I don't claim to fully understand projected lights.  Maybe this is something that varies by viewer & gpu driver.  In any case - I tried hiding some projected lights.

I have five lights projecting.  The three closest lights I enclosed in hollow spheres.  The spheres are textured blank on the outside, transparent on the inside.  There are two more lights (not shown in the photo) ten meters to the right.  I put up two flattened cubes, blank and white.  One between me and the lights.  The other behind me.  Nothing hidden for me.

  Photo below.

[Qie Niangao]

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Qwalyphi Korpov wrote:

I have five lights projecting.  The three closest lights I enclosed in hollow spheres.  The spheres are textured blank on the outside, transparent on the inside.  There are two more lights (not shown in the photo) ten meters to the right.  I put up two flattened cubes, blank and white.  One between me and the lights.  The other behind me.  Nothing hidden for me.

Just tested again and you're right: I'm not replicating that effect now, either. I don't know if something has changed, or if what I saw before was subtly dependent on something I'm not doing now.

[Coby Foden]

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Qie Niangao wrote:

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Qwalyphi Korpov wrote:

I have five lights projecting.  The three closest lights I enclosed in hollow spheres.  The spheres are textured blank on the outside, transparent on the inside.  There are two more lights (not shown in the photo) ten meters to the right.  I put up two flattened cubes, blank and white.  One between me and the lights.  The other behind me.  Nothing hidden for me.

Just tested again and you're right: I'm not replicating that effect now, either. I don't know if something has changed, or if what I saw before was subtly dependent on something I'm not doing now.

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What I noticed in projected lights is that:

• If there are one or two projected lights shining on a prim then their light will not go through a prim.

• If there are more that two projected lights shining on a prim then then some of the projected lights will go through a prim.

Note: The light ambiance must be zero, else the light will go through a prim.

[Qwalyphi Korpov]

I'll just add that all of my projectors had ambiance set to 1.