A couple of nooby questions about huge uploads.

[PheebyKatz]

I did some searching, and found some stuff as recent as 2017 concerning how to upload humongous decor and have it actually look right. I will sometime soon be needing to know just how to do this properly, and I have a couple of questions.

1: Considering the fact that I'd be using the same size textures either way, how much does it matter what size my actual model is when I upload it? Does size of the mesh at the time of upload make any noticeable difference in the quality of the final result, like a model imported at full-size vs. a model imported small-scale and then resized?

2: For detailed work at over 64 x 64 meters, does everything still work pretty much the way it did in 2017, or have their been any significant changes as to how to ensure upload quality? Will the info out there still produce optimal results (like using cubes to slice the mesh, etc.)? Or what do people do now that's different?

I realize it's probably silly, but I figured these two questions would be easy for anyone who knows. I know I should probably know all of this already, but I'm used to just uploading things and then blowing them up to scale, so it'd be great to know if that's the worst way of doing it, and what would be better. At least trying to go for best practices here for this one.

Edited March 5 by PheebyKatz

[PheebyKatz]

Judging by the lack of response, either nobody knows anything new, or nobody cares.

Either way, good to go.

Now watch everyone tell me they would have done it differently once it's all finished. XD

[ChinRey]

1 hour ago, PheebyKatz said:

Judging by the lack of response, either nobody knows anything new, or nobody cares.

Awww, I didn't notice your post until now. 😉

On 3/5/2024 at 3:47 AM, PheebyKatz said:

1: Considering the fact that I'd be using the same size textures either way, how much does it matter what size my actual model is when I upload it? Does size of the mesh at the time of upload make any noticeable difference in the quality of the final result, like a model imported at full-size vs. a model imported small-scale and then resized?

It makes no difference whatsoever so do it the way you prefer.

On 3/5/2024 at 3:47 AM, PheebyKatz said:

2: For detailed work at over 64 x 64 meters, does everything still work pretty much the way it did in 2017, or have their been any significant changes as to how to ensure upload quality? Will the info out there still produce optimal results (like using cubes to slice the mesh, etc.)? Or what do people do now that's different?

I'm not sure I understand the question. Can you give us a link to that 2017 post you found?

Here are a few general rules for splitting a mesh into a linkset though:

• Try to keep the distance between the center of each part to less than 64 m. If it's bigger, you won't be able to link them. (This has changed since 2017 btw, the max link distance used to be 54 m.)
• If possible, avoid splitting parts that have the same texture. It's no big deal if you have to though.
• For optimal LOD and LI split big and small tris into separate meshes.
• For optimal LI, try to get the download weight and server weight of the linkset as equal as possible.
• If the linkset includes several identical elements (such as windows on a building), upload one copy and duplicate it in-world.

These rules often conflict with each other so be prepared to make some compromises.

2 hours ago, PheebyKatz said:

Now watch everyone tell me they would have done it differently once it's all finished. XD

Well, it's always easier to give feedback to a finished build than to some abstract questions so that can't be avoided. But you do know about the beta grid, right? You can do test uploads there for free and that's crucial if you want to improve your meshes without wasting tons of L$.

[PheebyKatz]

From 2017: 

From 2020: 

From 2014: 

Just posting these so you can see what kinda stuff I was referencing, and I should have done that in my original post. Kind of moot now, but my main wondering was about how to slice huge stuff up so as to avoid overblown uploads with poor detail. Your reply to the scale question renders it moot.

I realize physics models and such work better if there's a certain minimum size involved, but land masses were just the prevailing themes of the threads I found. Main thing was would decor items suffer if I uploaded them at saner sizes and inflated them.

Thank you SO much for replying. I already do the import-one-copy-of-multiples thing, because that just makes sense, and knowing it makes no difference what size the mesh is uploaded at helps a lot. It also makes sense (especially with LOD) to separate dense clusters of triangles from larger clusters of fewer triangles.

You're one of the more trustworthy sources for this kinda knowledge, so thank you again for replying. It means a lot to me.

Edited March 12 by PheebyKatz

[Porky Gorky]

1 hour ago, ChinRey said:

For optimal LOD and LI split big and small tris into separate meshes.

I'm new to mesh, at least the SL side of it. I’ve been focused on PBR materials since I've been back and I've been importing models to test them on, not really caring about optimising LI at this point. But something that has been bugging me is that I can import 2 models with the same number of polys and the same size bounding box yet they can have different Li. I'm wondering if your comment about triangle size is the answer because the only difference between the two meshes would be the size of the polys. 

So if possible could you (or anybody) please speak more about the triangle size? Is there an optimal triangle size (in cm)? Are there limits to how big or small triangles should be when trying to optimise the LI. Why are you suggesting that small and large tris be split into separate meshes? Thanks.

Edited March 12 by Porky Gorky

[ChinRey]

33 minutes ago, Porky Gorky said:

But something that has been bugging me is that I can import 2 models with the same number of polys and the same size bounding box yet they can have different Li. I'm wondering if your comment about triangle size is the answer because the only difference between the two meshes would be the size of the polys.

No, that's a different issue. The download weight, which is the weight that usually determines the land impact, is calculated from two factors, the calculated swap distances between the four LOD models (which again depend on the size of the object's bounding box) and the file size of each of them.

The file size depends partly on the amount of raw data of course but also on how much the compression algorithm (good old gzip) can compress the data and even minor differences in the data structure can have a significant impact on that.

Here's a seriously oversimplified digtal example to illustrate. Take the string 1000010000. It can represented as 2x(1+4x0). But move the 1 in the middle to 1000100000 and we get 1+3x0+1+5x0, a significantly more complex string.

 

50 minutes ago, Porky Gorky said:

Is there an optimal triangle size (in cm)?

No, there's no optimal triangle size, the rule is always to have as few as possible (but not fewer). However, with small triangles you usually need more of them, increasing the file size, and big triangles take up a lot of space, increasing the object size. So by combining them into a single mesh, you get both a relatively large and bounding box, increasing both the factors that determine the download weight.

So the general rule is to not combine big and small tris in a single mesh. But remember there is no rule without exceptions. Look at this little cottage for example:

The doorframe has 24 small tris and the window 28 so normally we want those as separate meshes. Normally they shuold have been done as separate meshes but this is a 1 LI house so it can only have two parts in the linkset. The door has to be separate to be movable so everything else had to be made as a single mesh. This is a good example of how the different rules for optimisation conflict with each other so you have to choose one or the other.

[ChinRey]

2 hours ago, PheebyKatz said:

Just posting these so you can see what kinda stuff I was referencing, and I should have done that in my original post.

Ok. I don't really have much to add to the replies I posted to those threads but I think I should emphasize one crucial and often overlooked trick I mentioned in both:

If you want to ensure seamless joints between two meshes, make sure the overall dimensions of each and the position of every single vertice along the seams are a precisely a number of millimeters that is divisable by 2. If you don't it can be very difficult, even impossible, to align them correctly in-world.

[vanettda Lassard]

I am, and I will forever be a n00b to mesh. However, I have learned a few things in my current learning curve with Blender and importing Mesh in to SL. For instance I tend to build relatively small and when it is imported to SL--when I'm done diddling around--I will enlarge it. Part of the reason I do this is just an economy of space. When I go onto the beta grid rather than sucking up a large swath of the sim with my build, I build small in Blender and test (relatively) small in-world. I see no difference in the textures or mesh beyond the Li increase when I go big. I can still zoom in, around, and through my builds as if it were larger.

[PheebyKatz]

9 hours ago, ChinRey said:

Ok. I don't really have much to add to the replies I posted to those threads but I think I should emphasize one crucial and often overlooked trick I mentioned in both:

If you want to ensure seamless joints between two meshes, make sure the overall dimensions of each and the position of every single vertice along the seams are a precisely a number of millimeters that is divisable by 2. If you don't it can be very difficult, even impossible, to align them correctly in-world.

Totally. It's super important to remember that all the editor window stuff goes by Metric, and that it's gotta be able to align using the edit tools inworld.

And normals have to calculate properly on upload, as well. And probably a lot of other things I haven't even thought of, too. Math is our friend, if we look really close at what all of this is and work within its parameters. It's only sorcery to the uninformed.

Good advice, but then I wouldn't have expected otherwise. Thank you~!

Edited March 12 by PheebyKatz