Creating LoD models, case study 2, Lesson 5

 

Tutorials: Creating LoD models, case study 2, Lesson 5

Creating LoD models

Case study 2: Lesson 5 - Going low

I hate to make compromices but sometimes they can't be avoided. The chain of my sign isn't really noticeable at low LoD so I didn't really need it at all there. It is noticeable at the switch between low and lowest, when it suddenly pops up or vanishes, though, and because of that, I really wanted to keep it. However, simplified chain links wouldn't work since sudden shape changes between LoD models would be just as noticeable and since the low LoD model was so significant to the LI, a working chain representation would require far too many triangles. In the end I removed the whole thing and here's how the low LoD model turned out:



I couldn't remove the chain link face though and a single triangle there did more harm than good to the appearance so I hid it. Here's the bracket reduced to a single triangle:



What you don't see in this picture is that i's actually two triangles, facing in opposite directions, one assigned to the chain bracket face, the other to the chain face. Here I've moved one of them slightly upwards:



This trick has two functions, first, unlike what GLOD believes, it's usually better with no triangle at all than a single "eyesore triangle". The other function is to reduce the LI a little bit. With the vertices for the two triangles aligned perfectly with each other, the file becomes a little bit more compressable, reducing the download weight a little bit. Align your vertices consistently whenever possible and you can easily save 20-30% LI with no visible effect at all.

Here's a top view of the low LoD model:



Yes, it's hard to see what this picture illustrates but nearly all the triangles and vertices of the model are aligned with each other along the y axis. The only exceptions are the signboard face which has to be a bit away from the base plate to avoid texture flickering and the wall mount which may occasionally be seen from the edge even at low LoD. (Looking at that picture, I see where I could have done better but oh well, it's good enough to keep.)

Lesson 6 - The faraway