I have tried the
-r option, much better but slower than using micropolygons. But there is an important limiatatiom: the
-r option is not compatible with the
-u option, then is impossible to bake using only raytracing. I am using H 8.1.704 Linux.
I have guess that many of the problems are in the interpenetrating areas where, several planes intersetcs, here the micropolygins pattern is more noticiable.
Another option to improve the results is to increase the shading quality, but to expensive.
This is the best I have get using an occlusion surface shader with bump mappint and a shading quality of 5:
Still having errors and patterns.
I think that Mantra bake option needs a lot of improvement. Hope for H9.
Finally I have to return to LightWave to generate the occlusion pass