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Perrie Juran

RenderLODFactor...a question.

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height offset.jpg

 

We see on a regular basis people who have problems with seeing Sculpties posted in the Forum.  The universal answer is "raise your LOD Factor."

Now some TPV's such as Phoenix and Firestorm provide a slider (screen shot above) to do this quickly.

The other alternative is to go into the Debug settings for 'RenderLODFactor' and change the number there.

People recommend setting it higher than 4 which the Viewers allow.  But I am wondering if the higher setting actually makes a difference.  That even though the Viewer allows you to insert a higher number, that the detail still stops at "4."

I tried this out myself, starting at 1 and raising it by steps to 4.  I can see the change in detail as I raise the number.  But once I go over 4, I see no further improvement.  This could be that simply I have reached the limits my computer can handle.

So my question is, does raising the LOD above 4 actually gain anyone any improvement?

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Just a thought, the slider you show is maxed out at 4. Could it be that the viewer your using will not allow any setting above 4 no matter what you enter in the debug settings, it still only goes to 4? I would think that if the viewer could go higher the slider would not stop there but be able to go higher.

If you set it higher in the debug settings does the number at the end of the slider go that high, or does it still show 4? Like I said, just a thought.

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I believe the practical limit is 4. And if a sculptie does not look good at 4 (or even 2 - the 'High' setting for the LL Viewer) I would throw it away.

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In older viewers and mod V1 viewers like Cool VL, the Object slider is linked to the Debug "LOD Factor" as in they change the same setting and I know when I set them to 8 in debug (above the 2.5 max) it does make quite a difference. Only problem is a lot of people experience major crashing issues after, especially with a high draw distance and LOD factor. I Know nothing about V2/3/Firestorm viewers as they are useless to me, but higher LOD than the slider allows should work. I think 8 is the max though.

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Hitomi Tiponi wrote:

I believe the practical limit is 4. And if a sculptie does not look good at 4 (or even 2 - the 'High' setting for the LL Viewer) I would throw it away.

Good points.  I have some boulders I need to replace.

 

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There is a reason you see no difference after a setting of 4. The SL system supports 4 levels of detail. When we design a mesh object, we build in four levels of detail, four actual models of the object. Well, some of us do.

The Prims and sculpties use 4 LoD's generated by the viewer. Mesh objects download 4 models of the object, when the designed provides them.

As best I can tell the setting controls the minimum size model to use. LoD 4 being the most detailed model. When the viewer is set to LoD 4 it will ignore the lower poly models 1 to 3 and always show the LoD 4 model. There is a render speed hit for doing that. 

When objects are farther away we see less detail. Fewer polygons are needed to tell the computer how to color the smaller number of pixels a small object uses. When LoD is set, the viewer has to download the high detail model and render it. That can lengthen initial rez time by a little. Having to render EVERY polygon in the high detail model every frame regardless of where you can seem or not adds load to the viewer and decreases Frames per Second (FPS) for no improvement in visual quality.

I think the default setting is 1.x. Why real numbers work is a mystery to me. I'm not sure exactly what they do with the value. A setting of 2 improves things. If you can see a difference at 2 and your FPS is above 25, you should have no problem going to 3. As long as you can get 25 FPS keep turning it up. If you computer and bandwidth can handle it, go for it.

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I think the 'real numbers' part is that the LOD factor doesn't control WHICH LOD is seen, but the distances at which the LODs switch.

 

Put simply, at a RenderLODFactor of 4.0, the distance at which you will see the highest detal LOD of a sculpty/mesh 4 TIMES the normal distance at which it would switch.....which means that by the time it is far enough away to switch to the 'medium' LOD, it's so small on your screen that you can't even notice it.  Same with the switches to 'low' and 'very low' LODs.

 

While the actual calculations/distances involved are VERY complex, a simplified example:

 

Say that, at 1.0 RenderLODFactor, an object switches from "high" detail to "medium" detail at a distance of 10.0 meters, and from "medium" to "low" at 30.0 meters.  Switching to a RenderLODFactor of 3.5 would change the distances at which the switching occurs, to 35.0 meters and 105.0 meters, respectively.

 

And if the object is large enough, those distances get even bigger (larger items switch further away than small objecs, hence why they have a higher Land Impact.) and the effect of RenderLODFactor becomes even greater......great enough that by the time the object is far enough away to 'switch' to a lower LOD, it is outside your view-distance!

 

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Nalates Urriah wrote:

There is a reason you see no difference after a setting of 4. The SL system supports 4 levels of detail. When we design a mesh object, we build in four levels of detail, four actual models of the object. Well, some of us do.

The Prims and sculpties use 4 LoD's generated by the viewer. Mesh objects download 4 models of the object, when the designed provides them.

As best I can tell the setting controls the minimum size model to use. LoD 4 being the most detailed model. When the viewer is set to LoD 4 it will ignore the lower poly models 1 to 3 and always show the LoD 4 model. There is a render speed hit for doing that. 

When objects are farther away we see less detail. Fewer polygons are needed to tell the computer how to color the smaller number of pixels a small object uses. When LoD is set, the viewer has to download the high detail model and render it. That can lengthen initial rez time by a little. Having to render EVERY polygon in the high detail model every frame regardless of where you can seem or not adds load to the viewer and decreases Frames per Second (FPS) for no improvement in visual quality.

I think the default setting is 1.x. Why real numbers work is a mystery to me. I'm not sure exactly what they do with the value. A setting of 2 improves things. If you can see a difference at 2 and your FPS is above 25, you should have no problem going to 3. As long as you can get 25 FPS keep turning it up. If you computer and bandwidth can handle it, go for it.

Nice.  Thanks.

If I am understanding this correctly then the Server doesn't support more than 4 levels of detail so trying to "force" a higher level than 4 in the Viewer really has no practical benefit.

As I played with my setting sat my home, as I stepped up from 1 to 4 the difference in detail was distinct though how much the difference varied from sculpty to sculpty varied visually.  It did seem that the larger the scultpty the greater the visual appearance seemed. 

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