PLEA for LOD !!

Sculpties are great. But LOD sucks! Detailed sculpties get rendered badly for distances over 10 or even 5 meters.

I know everybody can change LOD-preferences in their individual viewer, but the average user doesn't. So PLEASE Linden, do something about LOD!

Are there any tips for better LOD?

This is a design issue: LOD is a fact of the technology used to render objects in three dimensions and sculptors have to take that into account when creating an object.

Of course you are quite right that adjusting the LOD display of your viewer is not an adequate design solution: most residents use the plain vanilla settings that SL sets automatically to match their hardware configuration on installation. It is bad design to assume that a resident will go to the trouble of resetting to an inappropriate LOD display (even if he or she knows how) because a sculpted object looks like crap.

I am still very new to sculpting but I have been working hard to get to grips with LOD. As far as I understand the issue, doubling up vertex points not only creates sharper corners and edges but it also improves LOD since each additional vertex point effectively increases LOD by an extra stage.

The recent implementation of oblong sculpt maps in SL has helped with this issue because they allow greater flexibility in the distribution of vertex points. I believe that only 64 x 64 sculpt maps were useable in viewers prior to the latest release, whereas SL will now accept any permutation of 4 that calculates 1024 pixels (ie: 256 x 4, 128 x 8 ...). Be aware, however, that older versions of the viewer will not render oblong sculpt maps properly, although the problem here is really a matter of choice for residents who insist on using inappropriate hardware and software to render SL.

Apart from that, the designer is obliged to decide the appropriate maximum distance at which the object will be viewed and deal with LOD accordingly. I have just finished a set of windows, which are rendered perfectly as far the graphics card can see, by using quadruples of every slice on the joints, frames and sills. I also finished a faucet for baths and sinks that use only doubles since it is unlikely that the object will be viewed from a distance of no more than several metres within an enclosed space.

In both cases the surface texture was compromised because only a portion of the objects' actual surfaces were being displayed. A 256 x 256 texture would look like a 128 x 128 on the windows, for instance. I got around this by doubling up different versions of the window in the same texture so that two adjacent windows appear to be different even though they are using the same 256 x 256 texture, which was flipped in one case.

Another trick to help cheat LOD is to make the sculpt map significantly smaller than its intended size for final use. This does not always work but it works often enough to make experimentation worth your while. The problem here is that the physics engine will 'see' a much larger object and avatars will accordingly bump off its larger but invisible 'real' size at unusual distances.

Thank you very much for your elaborate reply Ephraim. I only have a question about making the sculpt map 'significantly' smaller. Wings3D creates a sculpt map of 128x128, which suits my needs very well. Do you mean that I should make the bmp-picture smaller (for example in Photoshop) and create an alpha layer around it, but still keep 128x128 as the final size for upload?

I am not at all familiar with the range of sculpting applications compatible with SL, Paul, since I am still quite new to sculpting. An experienced user of Wings would be in a better position to advise you.

If it helps to explain how I work:

I use Sculpt Studio, which is an in-world device for creating sculpties. The process involves rezzing a number of slices, each with a number of vertex points, which are then edited using the in-world building tools.

The final sculpt map is generated by rezzing an edit frame, which is a box that is auto-adjusted to fit the shape. If the shape is, say, 2m x 3m x 1m, then the edit frame will auto-adjust to that size. A 64 x 64 sculpt map is obtained via an url provided in chat from which the sculpt map is downloaded to the hard drive.

In order to cheat LOD, I sometimes make the auto-adjusted edit frame proportionately larger - in this example, I could make it 4m x 6m x 2m or 6m x 9m x 3m. The final object will be respectively 2 or 3 times smaller when the sculpt map is applied in-world so the dimensions of the object just have to be increased accordingly.

I don't fully understand the solution you are proposing but from my observation, it seems that the spectrum of colour in different sized versions of the same sculpt map becomes considerably less vibrant as the proportion of the final object's actual size to the sculptie prim is decreased. The flow of colour on the sculpt map will be otherwise identical so it appears that colour gives shape and brightness gives size.

I can't say if this helps but you might be able to apply the basic concept to the application you use and see if it works. Failing that, I suggest you get advice from an experienced user of Wings.