What is a 'normal'?

Blitz3D Forums/Blitz3D Beginners Area/What is a 'normal'?

Boiled Sweets(Posted 2004) [#1]
Hi,

erm what is a normal ie. the collision test CollisionNZ for example. COuld someone plese explain this to me.

Thanks.


scribbla(Posted 2004) [#2]
well dont quote me on this....but in lightwave a surface normal is the direction of the poly so i guess in blitz its the same, the direction a poly is facing x,y,z..i think ?




Boiled Sweets(Posted 2004) [#3]
So CollisionNX, CollsionNY, CollisionNZ?


electronin(Posted 2004) [#4]
I'm not sure exactly. I know it has something to do with lighting though (VertexNormal, VertexNX, VertexNY, VertexNZ
all have to do with the way a mesh looks with a light).


Jeppe Nielsen(Posted 2004) [#5]
Yes what tiler says, a normal is a vector with a length of 1. Basically it is a "line" or direction that tells which way a surface or vertex(a dot objects are made of) is facing. So if a normal's coordinates are x=0, y=1, z=0, then the polygon is facing up. Normals are useful for a lot of stuff, i.e lighting, collisions, etc.


scribbla(Posted 2004) [#6]
ummm i might look in to this..i never thought of using them before...could bounce of walls in opposite direction normal facing...interesting...does it come back negative and positive <0 or >0 so you know if its left or right


Boiled Sweets(Posted 2004) [#7]
Yes it returns + or - normals...


ralphy(Posted 2004) [#8]
TILER,

Do you post on the Fable boards? Im sure I recognise your sig pic.


scribbla(Posted 2004) [#9]
ralphy
fable...no i never heard of it...is it any good


Clyde(Posted 2004) [#10]
Cool Boiled Sweets, how've you got on mate?


Boiled Sweets(Posted 2004) [#11]
Yep I use them now for collision detection - works a treat - thanks all...

The first ever test demo version of my new upcoming game will be out this week...

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