Puzzle re optimising texture size & UV

[Bitsy Buccaneer]

This is the generically unpacked UV for a piece of my current project. It's probably good enough for what I'm after.

All of that blank space sends horrors of texture inefficiency up my spine however. But does that still matter if I use a 256 seamless repeated texture instead of a fancy baked shadows one?

I can't see how it would, because a 256x256 is a 256x256. It's going to bug me if it's just my guess though.

Hopefully that's clear enough because trying to write more is just confusing me. :matte-motes-smile:

[IvanBenjammin]

Its height to width ratio is about 8:1, which means you can use a 1024x128 texture, or 512x64 if you want to be super optimized.

I'm not sure how UV aspect ratios work in Blender, but generally speaking you want to stretch out your UVs to fill the whole width, and just use a rectangular texture. You'll notice that the UV grid is 8x8, which is very helpful when working out the aspect ratio of textures.

[Aquila Kytori]

Hi

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Bitsy Buccaneer wrote:

 

 

All of that blank space sends horrors of texture inefficiency up my spine however. But does that still matter if I use a 256 seamless repeated texture instead of a fancy baked shadows one?

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In this case ...No it doesn’t matter.

The UV map layout is not a texture. It is a list of X, Y  ( U V ) co-ordinates in the Collada file of your mesh.

If you are planning  to use a seamless texture on the mesh in world  and adjusting the horizontal and vertical repeats then leaving all that space is not being inefficient with your texturing.  Using repeating seamless textures like that is probably the most efficient way of texturing things in SL.

As far as texture efficiency is concerned, for seamless repeating textures applied in world, using UV map 1 or UV map 2 makes no difference.  See Image below :



But………. The texture will not be seamless !  

If you look carefully on the mesh that uses UV map 1 or UV map 2 you will notice a vertical seam.

To make it “seamless” you would need to straighten out at least  the left and right hand edges of the UV island and then scale it in the X axis with UVs > Constrain to Image Bounds enabled so that those edges are perfectly aligned to the edges of the UV space.

In UV map 3  I used the Blender UV mapping option Follow Active Quads then scaled it with Constrain to Image Bounds enabled in Blenders UV image editor.

 

Unwrap using Follow Active Quads .  (1 method)

In Face select mode :

Select one quad of your mesh , U  > Reset

Select the rest of the mesh  L

Unwrap   U > Follow Active Quads

UV Editor :    UVs > Constrain to Image Bounds

Then you need to scale the UV island so that it fills the UV space completely.

Note when doing this I unwrapped the end faces separately and scaled to suit.

 

Depending on the texture you are using the seam may hardly be noticable, in which case using your original UV map will be ok

 

[arton Rotaru]

I would say, it depends. If the 256x256 is used elsewhere in the scene already, it doesn't matter. If this 256x256 is loaded only for this particular mesh, it's a waste when a 32x256 would be sufficient.

[Bitsy Buccaneer]

Aquila & arton, I took all of that on board straight away, said yes I understand it, the basic layout is ok for the mesh bit, need to fine tune the sizing for the texture, thought now i know how to do that active quads thing sort of maybe and maybe some jiggle will be good for this project (so it's not too repeaty) and maybe it won't, things to try, and then promptly dove head first into making myself crazy trying to get a background pattern suitable for tinting so i can use the same 64 x 256 for every metal bit in this playground and still have them in lots of bright colours. At which point it seemed eminently sensible to take on animations.

So sorry for the delay and thank you as always for your help in untangling one of my many brain knots. You two are stars. :matte-motes-smile: