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Making sense of things....


Anna Nova
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I'm making a serious attempt at making good LODs for last year's build of our octagon house.  Because, in ignorance, we made it terribly.  You can see it at   http://maps.secondlife.com/secondlife/Ogilvie/134/81/71  and here's a picture.

House before_001.png

The non-dome walls are made of flat panels, and were made with Mesh Generator, and textured using seamless textures in world.

I had planned to take the DaEs into Blender, change the tris to quads, merge co-incident verts, remove some faces that aren't visible, and then using nodes bake a single 512sq texture on it.  Then bake the same high-poly texture onto a simplified mesh for the medium, and put that image onto a plane imposter for the Low/Lowest.

However, I am getting thwarted by my lack of understanding.  I tried 5 different uploads in beta using the Second Life Viewer (and Firestorm viewer, I'm on Linux, so I expected the results to be almost identical and they were)

These are the results of one mesh set.

  Triangles Vertices Download Cost
Mesh Generator object  (MGO) 7672 6322 3.846
Import-Export no triangulation 7672 6306 3.975
Ditto Tri-Quad, Triangulation on export 7672 6306 3.975
Ditto plus a Smart UV-Map 7672 7235 5.263
Fully optimized mesh with detailed UV-Map 7432 6707 6.475

So a couple of observations/questions.

  • The MGO is obviously quite good, and has preserved the materials, and comes in very low Land Impact.  DL is the highest of the LI factors by far.
  • Blender does a good job of turning triangles back to quad and vice-versa - in fact you can't see a difference.
  • Adding a UV Map seems to add Vertices.   Is this right?  Is there an extra cost associated with UV maps?  Or have I done something stupid?
  • Reducing Triangles seems to make the DL cost go up.  I was not expecting that.  Why?

and I haven't even started to make that Medium LOD yet......

Thanks for your wisdom.

Edited by anna2358
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1 hour ago, anna2358 said:

 

  • The MGO is obviously quite good, and has preserved the materials, and comes in very low Land Impact.  DL is the highest of the LI factors by far.

Mesh Studio certainly tend to create more "SL firendly" dae files than Blender and as far as I know, there are only three Collada libraries written in JavaScript so it's very likely that Mesh Generator and Mesh Studio use the same one (Three.js is maybe the most plausible candidate).

 

1 hour ago, anna2358 said:
  • Adding a UV Map seems to add Vertices.   Is this right?  Is there an extra cost associated with UV maps?  Or have I done something stupid?

Technically the mesh has a UV map already, all functional prims, sculpts and meshes in SL do. The UV map decides how the texture is spread across the surface and without it there won't be a texture there at all, only a single pixel used to cover the entire face.

But you use Smart UV mapping to redo the UV map. It's not something I have noticed before but it doesn't surprise me. Blender's smart UV map tends to break a material into as many isolated islands as possible, Among other things that means there will be many vertices with multiple UV coordinates. Second Life does't allow a vertice to have multiple normals or be assigned to multiple faces. If they do, they will be split. It makes perfect sense if that applies to UB coordinates too.

 

1 hour ago, anna2358 said:

 

  • Reducing Triangles seems to make the DL cost go up.  I was not expecting that.  Why?

The vertice count is far more important to the download weight than the triangle count.

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32 minutes ago, ChinRey said:

The vertice count is far more important to the download weight than the triangle count.

I see what you say about the Smart UVMap, My optimized ones may be even worse, because my objective is to isolate materials for baking.  However I managed to reduce both Tris and Verts, and yet the DL cost went up  (Smart to Optimized).

I guess I need to do better on the vertex saving and the UV Mapping.

 

Edited by anna2358
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7 hours ago, anna2358 said:

I see what you say about the Smart UVMap, My optimized ones may be even worse, because my objective is to isolate materials for baking.  However I managed to reduce both Tris and Verts, and yet the DL cost went up  (Smart to Optimized).

I guess I need to do better on the vertex saving and the UV Mapping.

 

It would probably help if you uploaded a screenshot of your map, but yes, in MOST cases "SmartUV" ain't that smart and really doesn't do the best of things. That being said I am having a hard time with your "isolate your materials for baking" comment.  Maybe you really aren't thinking about your UV mapping in the best way?  If you mark your seams by hand  and you assign materials, the ISLANDS can be anywhere on the UV map mixed in with all the other materials -- this using Cycles which I understand you are using most of the time. 

IF you want something that looks much like a photo of one of your 8 sides, then perhaps "project from view" would be a starting place. That will NOT of course map anything correctly that isn't visible; you would need to go back and map those pieces separately. 

I actually really enjoy UV mapping -- it is like a puzzle but it does take both logic and practice. 

Below is a screenshot of a very complex UV map that I did today. I can't show you the object *wink* but you can see that the materials are scattered hither and yon IN THE ISLANDS THAT I MARKED. It doesn't matter WHERE they are on the map if you are baking.  Even if you are using tiling textures the pieces can be anywhere as long as they are aligned correctly. Any brick pieces -- while they do not need to be contiguous, DO need to line up  of course, but you can test that in the 3D viewport by looking at the object in MATERIALS view (I am pretty sure you know that just putting it in here anyway :D).

I am personally questioning the 512 texture choice unless this is JUST for the brick area?  I can't imagine a clean and semi-clear bake for that big whole panel on a 512 for the finished texture. But maybe I am just unclear about what you are trying to do. 

It is almost always faster and easier to just remake an old build, but I redo anyway from time to time as we can certainly see (easily) how far we have progressed. 

Good luck and have fun.  And let us know how it turns out! 

 

uvmap.thumb.PNG.3187475f2e43270defe271a7660e3e47.PNG

 

Edited by Chic Aeon
somehow ended up with two copies of the screenshot :D
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5 hours ago, arton Rotaru said:

So how did you do your uploads then? By generating the LODs in the viewer?

For the beta tests, by setting the med, low, and lowest LODs to zero in the uploader.  That is what I am working on learning how to avoid and still achieve an acceptable result.

What I still can't understand is why a mesh with lower triangles and vertices counts comes in with a significantly higher download value.

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14 hours ago, ChinRey said:

Technically the mesh has a UV map already, all functional prims, sculpts and meshes in SL do.

Yes but:

14 hours ago, ChinRey said:

Among other things that means there will be many vertices with multiple UV coordinates

Which means more data.

2 hours ago, anna2358 said:

What I still can't understand is why a mesh with lower triangles and vertices counts comes in with a significantly higher download value.

If you compare the SL imported meshes from a viewer, you will notice that each SL face is a separate plane AND it takes its own square UV space. Being separated like that, each single vertex gets one UV vertex, which means the corners are made of double vertices overlapping on the same spot. Apparently, it's more costly to have 2 UV vertices on one 3D vertex rather than the opposite. The uploader tries to do that indeed, splitting the mesh into material sub-meshes. Most likely, the more common UV vertices are referenced in all the submeshes, the higher its download cost (more stuff written to file)

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2 hours ago, anna2358 said:

For the beta tests, by setting the med, low, and lowest LODs to zero in the uploader.  That is what I am working on learning how to avoid and still achieve an acceptable result.

What I still can't understand is why a mesh with lower triangles and vertices counts comes in with a significantly higher download value.

I would suspect it is differences in the LODs then. The importers LOD generator is nondeterministic. It can do something different each time you upload the same mesh.

To get comparable results it requires all custom LODs to begin with.

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On 11/02/2018 at 2:45 AM, Chic Aeon said:

It would probably help if you uploaded a screenshot of your map, but yes, in MOST cases "SmartUV" ain't that smart and really doesn't do the best of things. That being said I am having a hard time with your "isolate your materials for baking" comment.  Maybe you really aren't thinking about your UV mapping in the best way?  If you mark your seams by hand  and you assign materials, the ISLANDS can be anywhere on the UV map mixed in with all the other materials -- this using Cycles which I understand you are using most of the time. 

IF you want something that looks much like a photo of one of your 8 sides, then perhaps "project from view" would be a starting place. That will NOT of course map anything correctly that isn't visible; you would need to go back and map those pieces separately. 

I actually really enjoy UV mapping -- it is like a puzzle but it does take both logic and practice. 

Below is a screenshot of a very complex UV map that I did today. I can't show you the object *wink* but you can see that the materials are scattered hither and yon IN THE ISLANDS THAT I MARKED. It doesn't matter WHERE they are on the map if you are baking.  Even if you are using tiling textures the pieces can be anywhere as long as they are aligned correctly. Any brick pieces -- while they do not need to be contiguous, DO need to line up  of course, but you can test that in the 3D viewport by looking at the object in MATERIALS view (I am pretty sure you know that just putting it in here anyway :D).

I am personally questioning the 512 texture choice unless this is JUST for the brick area?  I can't imagine a clean and semi-clear bake for that big whole panel on a 512 for the finished texture. But maybe I am just unclear about what you are trying to do. 

It is almost always faster and easier to just remake an old build, but I redo anyway from time to time as we can certainly see (easily) how far we have progressed. 

Good luck and have fun.  And let us know how it turns out! 

Chic, you were right I needed 1024 texture to get sufficient geometry.  My learning curve has been almost vertical - and I thought I knew Blender....

I'm finally making progress on this.  It is an artform in it's own right, especially the UV-mapping and the Lighting.  Here is my first reasonable attempt:

Solarium-bright.png

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To evaluate a UV map packing, it would be useful to also know what the actual 3D size of the object is (and along with that, the surface area). If there are too many pieces, a texture might not be sufficient, it all depends on how many inworld square meters this texture has to cover.

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26 minutes ago, OptimoMaximo said:

To evaluate a UV map packing, it would be useful to also know what the actual 3D size of the object is (and along with that, the surface area). If there are too many pieces, a texture might not be sufficient, it all depends on how many inworld square meters this texture has to cover.

It's a 9.7m x 5.3m x 0.3.  Here it is in Blender:  I am still working on the nodes.

 

5a883161ece46_Screenshotfrom2018-02-1713-41-58.thumb.png.cd2c06bb2cda0c1bfaa67736ea069a3d.png

Edited by anna2358
position picture correctly...
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4 hours ago, anna2358 said:

Chic, you were right I needed 1024 texture to get sufficient geometry.  My learning curve has been almost vertical - and I thought I knew Blender....

OH SWEETIE!  I don't think we EVER  "know" Blender LOL. 

 

Quote

I'm finally making progress on this.  It is an artform in it's own right, especially the UV-mapping and the Lighting.  Here is my first reasonable attempt:

 

Nice and neat without a bunch of overlap (I sometimes miss that part and sometimes it works and sometimes it doesn't).

My main thought would be that typically textures with very little pattern can be smaller than textures with a lot of pattern like woodgrain (that you likely want to look LIKE WOODGRAIN LOL).   So solid color areas can often be smaller than areas that need more pixels to show the pattern. 

THERE ARE EXCEPTIONS to this of course. I recently made a whole 35 x 45 building (no floor or ceiling but portico and stairs) on one 1024 texture INSIDE AND OUT. This was supposed to look like sandstone and while the texture is large and blurry it works for what it needed to be. Can't show you; Fantasy Faire. But it IS possible (and yes, I am a bit surprised). 

My only other big hint would be to use a grid pattern to check the ratios on your UV, This is especially important on woodgrain and fabric with patterns and of course you don't have that here. But even with solids your bake can get off looking if one say window trim takes up more area on the texture plain than another. Note sure if I showed the grid thing in the tutorials and your map here looks very reasonable but of course I can't compare it really :D. YOU can. Just something to think about down the line.

Here is the grid I use. You can swap it out for the texture used for the material and then put the real one back after you have things adjusted as needed.

grid.thumb.png.ae6ad2c7bdffbdb43bf15ce08744812c.png

Quote

Solarium-bright.png

 

Edited by Chic Aeon
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I am going to side with the "little bit blurry" over the possibly five 1024 textures and clear here. After all the conversation with our new eye-opening Firestorm tools and eight or more 1024 textures on tiny objects? OMG.

Personally I am much more comfortable with blurryish textures on LARGE items than on small which likely doesn't make sense to some folks. I have been working HARD not to overkill it with the large textures as that was a downfall of mine.

That being said YOU are the only one who can judge what works for you AND it will also depend on the needs and who will be viewing. For a big and busy event, I opted overall on "blurry" LOL. Actually my landforms had to be blurry since they are so huge.  One is over 100 meters. 

So in my mind, different circumstances will call for different plans. 

I hadn't planned on putting this texture in but it happened so I'll go with it. The reason this works (for me) is that it is a very organic build and will mostly be seen from a long distance. The light and shadow work well and really the whole point of the installation is MOOD.   

I also have used a 1024 for a set of books which are of course MUCH smaller LOL.    I guess I am just saying that I believe it is good not to get too caught up in "musts". :D. 

temple complete.png

Edited by Chic Aeon
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2 minutes ago, OptimoMaximo said:

You should be aware that a 1024**2 image equals 36.12 centimeters square paper sheet, with a density of 28.346 pixels/cm. The baked lighting can be very good, but it's gonna be very blurry.

I'm aware, but thanks.  The key here is that in High LOD the texture is mostly color - with a little graininess - the detail comes from the relatively high poly of the struts and edges.  At Medium LOD (and Low and Lowest are set 'use above' right now) you can't really see that sort of thing anyway, even with viewer LOD 1.0.

I think following Chic's and your input, I may remap it so that the wood, just the window frames in fact, are bigger in the UV Map.  At the moment that UV-map is what Blender does for an unwrap - without manipulation - just careful seaming.  And as I have 10 of these to do for the house, and would want them all to be to-scale with each other, I don't really want it too fiddly.

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4 minutes ago, anna2358 said:

At the moment that UV-map is what Blender does for an unwrap - without manipulation - just careful seaming. 

Definitely one of the most dangerous areas for new to Blender folks. It still constantly will turn pieces to 90 degree angles just to fit things in. That SO DOESN'T WORKS LOL.  Of course it took me a very long time to figure that out :D.

Go forth and play with those puzzle pieces and enjoy.   And I am off to work. 

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3 minutes ago, Chic Aeon said:

I am going to side with the "little bit blurry" over the possibly five 1024 textures and clear here. After all the conversation with our new eye-opening Firestorm tools and eight or more 1024 textures on tiny objects? OMG.

Personally I am much more comfortable with blurryish textures on LARGE items than on small which likely doesn't make sense to some folks. I have been working HARD not to overkill it with the large textures as that was a downfall of mine.

That being said YOU are the only one who can judge what works for you AND it will also depend on the needs and who will be viewing. For a big and busy event, I opted overall on "blurry" LOL. Actually my landforms had to be blurry since they are so huge.  One is over 100 meters. 

So in my mind, different circumstances will call for different plans. 

I agree.  Let's be clear, unless someone really really wants a copy of this house, and is prepared to sign a Support-Free contract at an exorbitant amount, this is a one-off for our parcel.  Most people won't look twice as they pass, and anyone visiting will have to be polite, 'cos I control the ban-switch.  It's for fun, and the joy of knowledge.

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1 minute ago, Chic Aeon said:

Definitely one of the most dangerous areas for new to Blender folks. It still constantly will turn pieces to 90 degree angles just to fit things in. That SO DOESN'T WORKS LOL.  Of course it took me a very long time to figure that out :D.

Go forth and play with those puzzle pieces and enjoy.   And I am off to work. 

Ya, but they are mostly just colored bits.....  But I get the point.

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24 minutes ago, Chic Aeon said:

I am going to side with the "little bit blurry" over the possibly five 1024 textures and clear here.

You're making an assumption on your own. If you thought that the whole surface area should be covered by the same amount of square centimeters/1024 textures, you're missing the point by not including the re-scale factor introduced by the use of a monitor. 

My advice is to build in modules, where smaller surface areas (like the window frame) get their own, smaller texture, so that the main surface, the wall, can get more area on a bigger texture alone (and the window becomes a prefab you can reuse somewhere else in the same design).

33 minutes ago, Chic Aeon said:

Personally I am much more comfortable with blurryish textures on LARGE items than on small which likely doesn't make sense to some folks.

Indeed it doesn't. There are sizes other than 1024, you can make some parts' UVs to catch at least the same number of pixels they had in a combined 1024 map in one or two 512 as separate materials, for example, gaining resolution at reasonable price. Not only you can achieve a smaller object using multiple smaller textures, for higher pixel density and saving on texture memory(**), but you can have series of assets that keep a design consistency, instead of a varied array of looks. Plus you get a prefab template to reuse across different items in the same project, same texture, upload once and duplicate inworld: save in upload fees and on texture load.

** saving on texture memory is meant in comparison to just splitting into more, same sized textures

37 minutes ago, anna2358 said:

I'm aware, but thanks.  The key here is that in High LOD the texture is mostly color - with a little graininess - the detail comes from the relatively high poly of the struts and edges.  At Medium LOD (and Low and Lowest are set 'use above' right now) you can't really see that sort of thing anyway, even with viewer LOD 1.0.

Which is a choice, that allows you to step onto different routes. My comment was meant to point out that any surrounding item should then account for this and use the same or similar pixel density on their textures. You can use colored meshes and make beautiful cartoon stuff with very small textures and a bit of shading, what's important is that all blends together. Too much of resolution difference between objects isn't good to see.

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For an automatic packing this does look quite good. Although these mostly rectangular shells are quite easy to pack anyways. What can be seen on this packing is the method one does use to pack UVs by hand as well. You start out with the largest shells at the bottom left corner, and work your way up to the smallest shells.

I don't want to give any artistic advice, though, I have to agree with Optimo, this wall piece cries for modularity. :) (look, no swingers)

Since Texel Density is mentioned yet another time, the guy who created a very famous set of scripts for 3ds Max back in the day, which are called TexTools, which is what I use to check my texel density (well not mine, but on the meshes I make ^_^), has just recently released TexTools for Blender, which has a cool set of features including a texel density checker.

It's free as well. http://renderhjs.net/textools/blender/

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2 hours ago, anna2358 said:

Ya, but they are mostly just colored bits.....  But I get the point.

Yes, as I said yours looked fine --- just something to keep in mind.

 

And I just wanted to say IN GENERAL that it is important for people who read these threads (have talked to a few inworld lately who IMed me to chat) to keep in mind that everyone models differently and what works for some may not work for others. There is a lot of "absolute" type comments on this forum (not just this thread but MANY threads). It is important to find YOUR OWN METHOD and not just take someone's word that their way is THE way. Experiment and find your own happy medium. This is supposed to be fun. This is supposed to be art.

 

Hopefully I never sound like I think everyone must do things MY way and that other methods and choices are wrong. If it seems I do, then just ignore my comment as that wasn't my intent. 

It IS your work and you DO have choices that are YOURS.  Those capitals are important :D.

Some technical choices posters come closer together on (like not making matches with the same number of vertices that could make a nice house) *wink*. But "artistic" things are seldom agreed on; some of us like one look; others like the opposite.

So make your own choices that work for you. 

And I, of course, will make mine. 

 

Edited by Chic Aeon
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I have one more thought here as this bothers me a fair amount and came up on the Opensim forums a lot. 

We each look at the world differently and what might work for one person doesn't for another. That is OK!  We don't all need to agree that pink is a prettier color than blue  -- etc. etc.

And looking to authority figures (we better put that in imaginary quotes) is a dangerous thing as too much reliance on others can push you off your own path.

When I was first learning art a few decades ago, my art teacher (about my age) told me that a drawing I had made "didn't work". I had spent a long time on it and I was very happy with it. She couldn't explain WHY it "didn't work", just that it didn't. Well I could have taken her word as law and followed her directions to the letter. Instead I explored lots of ideas about form and line and color etc and found my own style and my own way. 

In the end I became fairly famous (famous not rich :D) and one night I met my old teacher coming out of a restaurant-bar. She was definitely tipsy and told me how happy she was that I had been her student.  She did teach me a lot, partly to decide for myself what was "good". We each need to pick the advice that will help us and discard that which will not. 

 

 

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Artist / Artisan.

I agree 100% with both Chic and Optimo/arton. 

100% with Chic because SL is primarily a hobbyist's platform. I'm guessing that the vast majority of creators in what ever field, scripting, animating, texturing, 3D modelling (prims or mesh) etc have had no formal training in those subjects. They do it because its fun, and some will even hope to make a enough L$'s to pay there way.

Often they learn things on a need to know basis only, and thats fine. Sometimes they try to apply everything they have learn't along the way and other times not.

As Chic has so often said in these forums  "its suppose to be fun" and from noob prim builder to amateur mesh creator they are usually proud of what they have managed to make. That is what makes SL so appealing to these amateurs, they can have an idea, and if they put in enough effort they  can often succeed in seeing their idea actualized. Maybe not perfect and may have taken months when a professional could have done the same in a few hours, but they should be and are rightly proud of their accomplishment.

Very few of these amateurs could expect to find RL work doing the same amongst professionals.

They lack the years of training of the artisan. They haven"t spent the time in class and or working along side the RL crafts persons. They haven't learnt the correct method. There is a correct method. The  correct method is the one that has been arrived at over a very long period and accepted in the particular trade as the most efficient to get the work done to a suitable standard in a acceptable time.

Optimo / arton can suggest we use the correct methods but unlike RL we don't have to follow their advice. In the real world workplace we would loose our jobs :) but this is SL where as Chic says  "make your own choices that work for you." 

I am not an artist but enjoy pushing vertices about so i'm more of an amateur artisan.

 

Anyways....

4 hours ago, anna2358 said:

I think following Chic's and your input, I may remap it so that the wood, just the window frames in fact, are bigger in the UV Map

Just mentioning this just  because:

Your texture map seems to have some parts that are identical to others? if so you  could perhaps gain some textures space by enabling snapping in the UV editor and stack those parts one above the other.

I5a8879df19c02_UVeditingstackingislands.thumb.png.9aef4c5d65faf3103b526a63798a72cd.png

 

2 hours ago, arton Rotaru said:

Since Texel Density is mentioned yet another time, the guy who created a very famous set of scripts for 3ds Max back in the day, which are called TexTools, which is what I use to check my texel density (well not mine, but on the meshes I make ^_^), has just recently released TexTools for Blender, which has a cool set of features including a texel density checker.

I am one of those few that usually enjoy editing UV maps but that looks awesome so have downloaded it already and will search youtube to found out how it is used.

(Unfortunately the gifs on that page are way too fast for me to make sence of)

 

 

 

Edited by Aquila Kytori
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1 hour ago, Aquila Kytori said:

Optimo / arton can suggest we use the correct methods but unlike RL we don't have to follow their advice. In the real world workplace we would loose our jobs :) but this is SL where as Chic says  "make your own choices that work for you." 

And I now make about 90 cents and hour (well maybe a bit more as I am faster these days) rather than the 90 dollars an hour I used to make in multi-media. 

And I am OH SO OK with that :D.

:SwingingFriends:

 

OK I had to come back and edit since while that quote sounds great and has been true in the past, I currently make half to 2/3rds of me RL income in Second life. Plus a little from Opensim :D. I trey not to lie unless it is purposeful LOL.

 

Edited by Chic Aeon
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