about terrains&normal-maps&image-quality..(just a id

[ThommyE]

since there seems to be quite some discussions about terrain renderes and such i thought i throw in another idea (which i didnt see so far in discussions related to this topic but might be intresting when it comes to performance/imagequality of rendered terrains).

befor is start.. thats what i did in this afternoon:
created a random terrain in blender (using a 128x128 patch and noise-texture)
i got a basic highmap.
next i created a normal map from it (using normals as texture-coordinates on a guarient-texture)
after that i made a copy of the terrain and reduced the polycount to a 10% of the original one,applied the normal map and gave it a quick render..

.. after tuning around a little i got a terrain which looked as highily detailed as the version with 10 times more polys ( near and far away. both)
i guess bump maps should do a simmilar job (thought normal maps really look good)

so in case anyone of you reading this thing and is writing a new terrain node i like you to concidder adding a special materialor a shadder ,too.
dont know what mathematical operrations are perfomed by blender but it cant be much worse than adding/substracting a few normal values.

this thing works best on hilly terrain, there you have fully detailed ground and you barely notice a difference the lower-resolution terrain in the distance.
on terrain with higher ups/downs you will still have the usual terrain-optimisation issues but they only are recognisable at the siluette of the terrain and not on terrain itself, cause it seems as bumpy as under your feet.
anyone else think this might get good resluts in realtime apps?
(ok its not 100%compatible with hardware which dosen't support normal mapping... but i would now a graficcard released in the last 4 years which wasnt able to do this. and bumbmap should be fixed in in many old cards,too)
so lets hear your opinion,

greetings
thomas e