Texture size and lag

[anselm Hexicola]

I am going to upload a mesh object made in Blender.

I always heard 1024 X 1024 = BAD; 512 X 512 = GOOD.

Is it better to make a 1024 texture for the whole mesh, OR divide it into "faces" with their own individual 512 textures?

(..not very clearly put, but I hope you know what I'm getting at...)

PS. one individual 512 texture for the whole mesh does not give enough clarity.

[Ciaran Laval]

It depends, there are a couple of factors to take into account, one is the size of the texture and the other is the number of textures, so although 1024 x 1024 is not encouraged, it is feasible to use one and be more efficient than using 512's overall.

There's a good wiki article here:

http://wiki.secondlife.com/wiki/Texture_Usage

It's also worth checking out the linked texture sizes article from that thread.

[Knutz Scorpio]

The file size of a 512x512 texture is about a quarter of a 1024x1024, so if you can do it with less then four 512x512 textures that'd be the way to go.

[LepreKhaun]

You can have one 1024x1024 replace four 512x512 textures on your mesh with a savings since each texture to be downloaded entails an overhead in its "fetch and get". It's just a matter of using offsets and sizing for which quarter of the large texture you wish to apply where.

 

However, you do lose the option of repeats using this optimization and your entire mesh will be "blurry" until the entire texture is downloaded. But, if if that isn't a concern, you can even take the idea further by having one quarter of your texture further subdivided into four 1/16ths (or 256x256 textures) for the smallish areas of your mesh.

 

And, of course, if you're doing UV mapping, there are ways of manipulating the relative sizes and placement of your islands to acheive the same result. In other words, make unimportant or smallish areas that don't require too much detail occupy less space on your UV map and arrange things to have as little wasted space as possible. Even "stacking" islands that could well have the same texture pattern showing can free up precious map space to allow enlarging the "important" islands that require finer detail.

 

As Ciaran Laval said, it depends. It is good to know all of the options one has to be able to pick and choose what may work best on your particular model.

[Fenix Eldritch]

If used excessively and improperly, yes 1024x1024 textures are BAD. And the sad truth of the matter is that on SL, 1024x textures are most definitely used excessively and improperly. The best thing content creators can do moving forward, is to produce more and more efficient content. Use less resources. SL's performance will improve for everyone.

A 1024x1024 texture consumes 3MB of video card memory. If the texture also has an alpha channel (transparency) in it, bump that number up to 4MB. That's a lot for one texture - especially when you take into consideration that this is on top of EVERYTHING ELSE being rendered on your computer's GPU. So you really must think long and hard before deciding to use a large texture like that.

What is the purpose of this object? Will it be large and generally be viewed up close? If so, then maybe you could consider using a large texture.

But if this is going to be a "small" object, like an avatar, vehicle, prop, or worn accessory, then you probably should not go with a 1024 texture.

Take to heart what LepreKhaun said with regard to relative island size/placements. Now that we have total control over UV mapping, we can cram every last corner of a texture with imagery. The important parts that need to be clear can be sized bigger in the texture - given them priority and a more crisp detail. Anything else can be scaled down to take up less space on the texture.

Consolidating multiple textures into one for a single mesh is great, but if that means using a 1024x texture, (or if you use four 512x's) you should really consider trying to bring that size down first. There should be as little unused space in the texture as possible.

[anselm Hexicola]

Thankyou for your replies. They gave me much to mull over.

(I should maybe say that my uploaded objects are just for my own amusement; ie. not to be distributed inworld/sold. They just get put on my own rented parcel. So they will not impinge on the general SL users' graphic experience. That said, I do try, if only for my own sake, to get it as right as I can.)

@Ciaran Laval - the notion of keeping the total no. of  "local" textures to a minimum is obvious now I think about it. Another aspect of good housekeeping to bear in mind.... But so often one jumps on to a new build/project, starting afresh in Blender and Gimp, without considering how they might be integrated.

@Knutz Scorpio - your arithmetic was what my original query was about. I freely admit that I am totally ignorant about the technicalities of how SL's rendering and users' graphics cards work; I just wanted a hint as to the best way to go.

@LepreKhaun - yes, I do tweak the UV mapping as best I can; it takes me ages, but I kinda like it! Generally my cheap and cheerful style of texturing is to do an AO then add other layers (colour, text..) Because of that, "stacking" isn't an option. Also I tend to keep my islands (perhaps too ) widely spaced - got snookered once when they were very close.

@Fenix Eldritch - you ask "Will it be large and generally be viewed up close?" Well, it is a shipping container; so - large?? And yes, the bits of texture that need clarity are only important close-up, specifically the labels on the doors.

 

I thought I would put on some screenshots so that the subject matter was less abstract.

Here is the UV map of one of the doors.

 

This is the texture itself in Gimp = x512.

 

 

And here is a general view of the mesh.

 

(...I now reckon I can keep the texture down to x512 with a bit of fiddling about with the UV map; but that means all my LOD's will need changing!)

[Drongle McMahon]

It is possible to use quite a lot of stacking combined with AO. However, it requires a lot of planning of the UV mapping and then exquisite accuracy in the location of the repeated parts of the mesh. The results can be very good for texture area/model area ratio, but it's seriously hard work, not to be undetaken without very compelling reason.

[LepreKhaun]

---

anselm Hexicola wrote:

Thankyou for your replies. They gave me much to mull over.

(I should maybe say that my uploaded objects are just for my own amusement; ie. not to be distributed inworld/sold. They just get put on my own rented parcel. So they will not impinge on the general SL users' graphic experience. That said, I do try, if only for my own sake, to get it as right as I can.)

...

@LepreKhaun - yes, I do tweak the UV mapping as best I can; it takes me ages, but I kinda like it! Generally my cheap and cheerful style of texturing is to do an AO then add other layers (colour, text..) Because of that, "stacking" isn't an option. Also I tend to keep my islands (perhaps too ) widely spaced - got snookered once when they were very close.

...

(...I now reckon I can keep the texture down to x512 with a bit of fiddling about with the UV map; but that means all my LOD's will need changing!)

---

Thank you for the screen shots, it gives us something we can make concrete suggestions on.

 

For instance, if you're never going to have stencilling on the inside of that door, you can probably drastically decrease the size of its UV island. Here I've made it 1/4 1/16th the size of what it was, rearranged the islands and tightened it all up just a bit. This cut the UV mapping required for this door in half.

If I found that arrangement caused too great of detail loss on the inner door surface, I'd consider shortening the two right hand islands, enlarging the inner door island (from its reduced size) 150% in height and doubling width then turning it on its side, where it would snug into the bottom right corner.

 

And, yes, this "fiddling around" is time consuming, no argument there. But once you get the mind set of big islands for detail areas, squish everything else as small as they'll go, it'll go quicker.

 

And you'll have the satisfaction of having crafted your model the best possible way.

 

{EDIT to correct scaling error- 1/4x1/4 = 1/16th. LOL]

[and AGAIN to show a larger interior door as described.]