i just heard a raytracer named pov-ray,what was it, does it powerful, how do i use in blender???
Check the JMS’s plug-in to export from Blender to POVray:
ha!!quick answer! thanks 
check the povexport script of RCRuiz, the povanim has problems with the normals, sorry for my english 
https://blenderartists.org/forum/viewtopic.php?t=58027&highlight=povray
normals? what do you mean normals?
normal mode? or something?
what we call normal is the perpendicular direction of a face.
With this information you can know if the face is up or down.
then what does it mean problem with normal?
sory i just cant get it… :-?
To come back to the original question. Is PovRay more powerful than blender or YafRay? In other words, does it provide quality improvement and if it does, can you even use these improvements by exporting from blender?
To understand normals, pick ANY mesh with multiple polygons, and click DRAW NORMALS in object options. Then click Flip Normals. Then flip it again. Repeat. Fun, eh? The face normal is the outside of the mesh.
I think questions about “normals” are discussing in school on mathimatics lessons. Am I right?
There is interresting, is povray render better then blender internal render? Can anybody comment it.
Ever seen their gallery?
Yes, it’s just as good as say mentalray and such.
povanim has no problem with normal but Blender and Povray itself have one . Povanim offers a tool to recalculate the normals found in Blender but it seems that there is no solution for the normals used by Povray :
http://news.povray.org/povray.documentation.inbuilt/thread/<[email protected]>/
You can test the normals exported by yafray (and used by the yafray2pov script) to see a real and true problem :
http://cobalt3d.free.fr/util/blenderfile/images/normales/index.html
You can test the layered light exported by yafray (and used by the yafray2pov script) to see another real and true problem :
http://cobalt3d.free.fr/util/blenderfile/images/lights/layers/index.htm
no i m just get confused 
“normal”
now i m reading your words
where is “DRAW NORMALS” bottom? sorry?
Select a Mesh. Tab to enter edit mode. In the Editing Panel Tool there is a button Draw Normals.
Sorry InTaipai, but the answer is yes. “Normal” is a mathmatics term and is discussed in school class rooms. Others hear have said it is a line perpendicular to a poly but that is only true in that the poly is part of a plane because by definition it is a line perpendicular to a plane.
Again sorry but this is rather hard to expain to someone who does not speek english but you can get a beter explination of a normal from a teacher of high level maths in your native tounge. I hope. Your best bet is one that teaches calculas.
In blender 2.41 when you edit a mesh there will be 4 panels in the buttons window The last one is in english labeled “Mesh Tools 1.” Draw normals is in the first collumn of that panel.