Edges...
 

1. why soft edge and hard edge is imp?Is it because, I wanna show this edge more prominently comparing to others?Or it also has some other job to do??

Something like, a pipe will have soft edge in the main body but the the outline of a groove, the edge should be hard.

The edge that pass through are white are soft edges and the ones indicated by red lines are hard edge.

EDGES:
http://i39.photobucket.com/albums/e1...e_hardedge.jpg
RESULT:
http://i39.photobucket.com/albums/e1...hardedge_2.jpg

and what is the meaning of edges having angle between 0 to 180?is it like soft hard edge?

2. Normal map don't work correctly if the hard edges are not kept separate.It is most likely those edges(!) has two normals of different angles.

so, it there any method of making a hard edge smooth without costing extra polygon.

the set normal angle button is what I think you are looking for.

In Maya 2009, this option is in the modeling menu set in the normals drop-down menu,
The number you set it too means that any angle which is less than that will be soft.

Therefore, an angle of 90 degrees would be soft if I set it to 91.


You can select an edge you want hard and set it to 0, and it will make that one edge hard. You can select a loop and do the same thing.


This tool is your best friend :bandit:

Thank you very much.

But I asked , what is the significant of hard and soft edge.Is it because to make something more visible and something less?

What is the importance of angle between 0 to 90(Excluding this 2 values)

Just a wild guess, but I would say it determines how the renderer calculates the normal of that face. If it's soft, it takes into account adjacent normals, if hard, then it maybe doesn't... am I on the right track??

EDIT: Or are you just asking what it's used for? Like soft areas vs. sharp edges...?

When you soften an edge, it makes it appear more rounded, and when you harden it, it looks sharp.

I am a bit confused about your question, so I am sorry if I am not answering it.

Do i need to use hard edge when the corner of a box is beveled?

What is the significance(is case of gaming) if the angle is 30(or any value except 0 and 90)

usually the bevel operator will make the edges soft except for the ones in the corner (show hard/soft edges and you'll see what i'm talking about)

as for your second question i think what stwert said holds for games as well.
it all depends on whether or not the game engine will read that data i guess...

hmm, i checked, but all edges of a simple cube becomes soft.

then , what about normal(something else different from gaming) modeling, what is the significant of different angles?Why should someone use them?