quantity How many UV Map are recommended?

[woroschilow]

Hello,

I want to build some jewelry and let the user choose the color of the diamonds and metals.
The question I have is, whether I can solve this with only one UV map which will be used by all models...
OR...
...should I give each model its own UV map?

Is this a big deal for land impact if I use more Maps?

I attached an example of another artist to show off how it could look like.

Regards

[Wulfie Reanimator]

Every object in SL is going to have its own UV map, even if they are all laid out identically. That said, you should always have matching UVs whenever possible, because it makes it the easiest to create multiple textures that will also work for every other gem type. Just make sure you don't use 1024x1024 textures.

[woroschilow]

Thank you for the Info!

Why not using 1024x1024?
Should I use bigger or smaller?

I would like to know, whether it will be smart to give every object-group (Diamonds, etc.) it's own UV map in order to get more details.
So each diamond could have its own space on the UV. To overlap everything will make every Diamond looks the same.

[Wulfie Reanimator]

5 hours ago, woroschilow said:

Thank you for the Info!

Why not using 1024x1024?
Should I use bigger or smaller?

I would like to know, whether it will be smart to give every object-group (Diamonds, etc.) it's own UV map in order to get more details.
So each diamond could have its own space on the UV. To overlap everything will make every Diamond looks the same.

Because the diamonds are probably pretty small (certainly not even 0.5 meters on any side), you can and should use a smaller texture, like 512x512 or even 256x256. The reason for this is because having a larger texture will take up more video memory in each user's own viewer -- which you don't have an infinite amount of -- and the texture is going to take up a tiny amount of space on their screen, so there is no benefit to using a larger texture as all the details in it will be simply lost to distance.

As for the UV thing, it really depends on what you want to do, and there are no wrong answers. There is no Land Impact penalty between the two options, and LI doesn't matter for attachments anyway. (There is no maximum LI limit to them.)

Edited March 6, 2019 by Wulfie Reanimator

[woroschilow]

Very good explanation!

Thank you very much for your time and advise!

Regards

[ChinRey]

23 hours ago, woroschilow said:

I would like to know, whether it will be smart to give every object-group (Diamonds, etc.) it's own UV map in order to get more details.

As Wulfie said, there is no absolute answer but there is one important rule:

Make the pixels count!

That is, fill up each UV map/texture as much as possible. All that empty space around the island take up VRAM and bandwidth too and they don't add anything to the final result.

 

23 hours ago, woroschilow said:

To overlap everything will make every Diamond looks the same.

One trick that often works, is to partially overlap the islands. If you can figure out a way to do that, you can get different patterns ut still save on texture use.

 

17 hours ago, Wulfie Reanimator said:

Because the diamonds are probably pretty small (certainly not even 0.5 meters on any side), you can and should use a smaller texture, like 512x512 or even 256x256. The reason for this is because having a larger texture will take up more video memory in each user's own viewer -- which you don't have an infinite amount of -- and the texture is going to take up a tiny amount of space on their screen, so there is no benefit to using a larger texture as all the details in it will be simply lost to distance.

To put that into perspective.

According to wikipedia, the most common monitor size for itnernet users is HD, 1366x768 pixels. That means even if you fill up the entire screen with a 1024x1024 texture, you still won't be able to see all of it in full resolution.

The most common monitor size for Steam users is FHD - 1920x1080 pixels - barely enough vetically to show a coplete 1024 at full resolution.

VRAM (video memory) is a special kind of memory, much faster than regular RAM and connected directly to the graphics card. The "safe" amount of VRAM is 1 GB, every reasonably modern computer should have at least that. Game copmuters typically have 4 GB.

A 1024x1024 takes up 4 MB of VRAM, a 512x512 1 MB and a 256x256 256 KB. So the number of textures you can expect to be able to use without running into VRAM related performance issues are:

Resolution	Regular computer	Game computer
1024x1024	250	1,000
512x512	1,000	4,000
256x256	4,000	16,000

That may seem like a lot but remember, those numbers aren't for a single item, they are for every single texture in the scene, every single texture on every single avatar there and even the graphics used by the user interface. Unless LL has done some changes recently, it also includes the profile pics of every single person on your friends list, every single group you are a member of and every single person in every single gruop chat you have open.

Bandwidth can also be an issue. With a regular Ethernet connection you typically get about 10 Mbit/s. That means it takes almost a second to downlaod a 1024x1024, half a second for a 512x512 and a quarter of a second for a 256x256. Caching helps a lot for the surroundings you usually are in and for your regular avatar outfit but every time you go to a new region or meet somebody new or change to a new outfit, the new textures will have to be downloaded.

Edit: Oh, and there's one more thing to keep in mind: high texture resolution may actually reduce the visual quality. The reason is that the graphics unit automatically scales down textures before it displays them and like all automatic processes, that doesn't always give the ideal result. Scaling to a realistic size before you upload, gives you better control over the end result.

Edited March 7, 2019 by ChinRey

[OptimoMaximo]

On 3/6/2019 at 9:31 AM, woroschilow said:

should I give each model its own UV map?

Just to make this clear: Second Life accepts only one UV Map, AKA UVSet. That is, it is a data block containing a set of UVs for the model, regardless whether those are overlapped and rendered on a per-material basis or not.

A model, ideally, can have more than one UVSet: you can layout the whole model UVs (or just a selection of it) in different, parallel and concurrent, UV layouts that can be used by different textures, hooking them up appropriately in the 3D software. Again, this is a feature that SL does not support and, therefore, we're all constrained to use one UVMap, that we can split and layout on a per-material basis, so your question should be: how many materials are recommended?

[woroschilow]

On 3/7/2019 at 3:19 PM, OptimoMaximo said:

how many materials are recommended?

 

How many are recommended?

 

@ ChinRey

Thank you for this information!

[ChinRey]

43 minutes ago, woroschilow said:

How many are recommended?

When you use custom textures that aren't reusable elsewhere - and you are in this case - the answer is simply as few as possible.

[arton Rotaru]

2 hours ago, woroschilow said:

How many are recommended?

As few as possible is certainly right. Ideally it's: 1 mesh -> 1 material. To keep draw calls/state changes as low as possible as well.

[woroschilow]

2 hours ago, ChinRey said:

When you use custom textures that aren't reusable elsewhere - and you are in this case - the answer is simply as few as possible.

 

2 minutes ago, arton Rotaru said:

As few as possible is certainly right. Ideally it's: 1 mesh -> 1 material. To keep draw calls/state changes as low as possible as well.

How to change the color with a HUD, if I should use only 1 material which only can contain 1 texture map?

Edited March 8, 2019 by woroschilow

[arton Rotaru]

5 minutes ago, woroschilow said:

How to change the color with a HUD, if I only can use 1 material which only can contain 1 texture map?

You can use more than 1 material indeed, if you need to. it's just the ideal case to have just one material per mesh. It's something to keep in mind in general, and think about while building.