LOD models - Blender workflow

[Samekh]

Hi I'm a beginner to intermediate Blender user and have just started playing around with building stuff and testing it out on the beta grid. I'm wondering what the best workflow is for creating LOD models?I know you can let SL determine them in the upload window but I want to have a go at creating my own custom LOD models.

Do you save & export .blend and .dae files as you go along - for example after applying each level of multirez or subsurf modifier etc. Or is it better to work backwards from your finished piece (using the decimate modifier to simplify the geometry)?? What's best practice? Also would like to know best way to know scale btw Blender & SL? Everything I'm making at the moment is huge when I import into SL (although I've now found the rescale window in upload diaglogue to scale them down!).

Thanks in advance,

Samekh xx

[Chic Aeon]

I am sure you will get lots of good advice here, but one video you might want to watch is "Kettle Quest".

http://blog.machinimatrix.org/optimizing-meshes/

And about size, I always scale my base mesh cube, cylinder etc.  (for furniture and decor items, not buildings) down to a couple of the larger squares on the grid and then zoom in. That is still bigger than I need usually but scaling down is pretty simple once you find the scale window *wink*. 

 

Note that if you are using the Linden viewer to upload (which by the way has a MUCH improved uploader view screen in the latest build) that the .slm file will remember your sizing down. So if you have been uploading on Aditi at .5 of the actual mesh size you most likely DON'T want to downsize when you get to Agni. I got caught a couple of times on that. So watch the window as it will tell you the actual size in meters. I "think" that is the only time the size variation changes a lot, but can't say for certain.

 

[Alisha Matova]

I highly doubt my method could be considered a 'best practice', but it gets the job done.

 

I finish my model completely,uv maps, baked textures and all, first. Then from object mode, I drag(shift d) out a new copy sideways. I then manually reduce its detail while adjusting the uv map to keep the textures in the right places. Once I've removed enough detail I quickly toggle into Bounding Box view and double check that the new model is exactly the same size as the original. Rinse and repeat for rest of the lods.

 

Blender 2.6 does have some fancy multirez tricks that help retain the uv mapping between levels too. Though, I haven't figured this newness into my workflow yet. Maybe someone else here has. =)

 

ETA: I found SL lod specs! http://wiki.secondlife.com/wiki/Mesh_and_LOD

[Gaia Clary]

While the method shown in the kettle quest still works, newer Blender versions make it much easier to reduce meshes without destroying the UV maps. So actually you can meanwhile:

 

1. walk top down and use the decimator modifier for example without destroying the UV map, or use the retopology tools...
2. or you walk bottom up and add more detail as need for Higher LODS, also without destroying the UV map

At the end i believe its a matter of what you are creating and how you create it. If you start with sculpting, then you might use the decimator modifier (top down) and maybe(probably) the retopology tools.

So there is no "right way to do it" there are only more and more options

 

[Aquila Kytori]

Hi

Re scale :

1 Blender unit will translate to 1 meter or u can toggle on metric units in th Scene>Units menu and then also the grid square size will show in the top left hand corner and dispalcement in the bottom left of 3D window

[Samekh]

Thanks Chic

That's invaluable information

Best,

Samekh

[Samekh]

Thanks Alisha,

That's how I was thinking I would probably do it. Just better remember to hit the save button each time!!

Sx

[Samekh]

Thanks to everyone in fact, (esp Aquila for those scale illustrations). Now I just need to improve my Blender skills...lol