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TFormVector or MoveEntity?

Blitz3D Forums/Blitz3D Beginners Area/TFormVector or MoveEntity?

Q(Posted 2006) [#1]
I don't understand the difference between TFormVector and its components: TFormedX(), TFormedY(), TFormedZ(), and MoveEntity. They seem to function the same.. Anyone care to explain the difference?


big10p(Posted 2006) [#2]
TFormVector simply transforms/converts a 3D vector from one coordinate space into another. I can't see what that has to do with MoveEntity, specifically.


Sir Gak(Posted 2006) [#3]
So, the TForm family is just about manipulating vectors? The MoveEntity is about assigning a position to a 3D Entity, so we can conclude that TForm functions can derive values to assign to the MoveEntity comand, insofar as knowing WHERE to Move the entity to?


Stevie G(Posted 2006) [#4]

So, the TForm family is just about manipulating vectors? The MoveEntity is about assigning a position to a 3D Entity, so we can conclude that TForm functions can derive values to assign to the MoveEntity comand, insofar as knowing WHERE to Move the entity to?



Pretty much for Tformvector & Tformnormal although tformvector can tell you how much an entity is to be moved, not it's new position. You would use tformpoint for that.

Tformvector 0,0,1, PLAYER , 0
translateentity PLAYER , tformedx(), tformedy(), tformedz()

is the same as ....

Moveentity PLAYER , 0, 0, 1


To be honest I use the tform commands all the time AFAIK they're some of the most useful commands in B3d.

Stevie


jhocking(Posted 2006) [#5]
tformpoint rawks


Sir Gak(Posted 2006) [#6]
Stevie G:
Pretty much for Tformvector & Tformnormal although tformvector can tell you how much an entity is to be moved, not it's new position. You would use tformpoint for that.

Tformvector 0,0,1, PLAYER , 0
translateentity PLAYER , tformedx(), tformedy(), tformedz()

is the same as ....

Moveentity PLAYER , 0, 0, 1


To be honest I use the tform commands all the time AFAIK they're some of the most useful commands in B3d.



Why use more when less wil do the same job? The Tform lines are two in number, with more info, and 'way longer than the much simpler MoveEntity command's line. So, why use the longer form? Just asking.....


jhocking(Posted 2006) [#7]
You wouldn't use it in that situation. That was just a simple example highlighting the difference between the commands.


Stevie G(Posted 2006) [#8]
A more practical example would be aligning single surface particles to the camera. Using moveentity for this would be a pain in the rear ...

Function PARTICLEupdate()

	If ( Not PARTICLEon ) Return

	s = GetSurface( PARTICLEmesh , 1 )
		
	For p.particle = Each particle
	
		If p\Life > 0
			;life / movement
			p\Life = LIMIT( p\Life - p\fade ,0 , 1.0 ) 
			VECTORadd( p\Position , p\Velocity )
			;uv's
			u1# = PARTICLEuvMulti * ( 7.0 - Floor( p\Life * 8.0 ) ) +.5/128.0
			u2# = ( u1 + PARTICLEuvMulti )
			v1# =  PARTICLEuvMulti * p\ID  
			v2# = vs + PARTICLEuvMulti
			;face the camera
			TFormVector -p\size,0,0, Camera , 0
			xx# = TFormedX()
			xy# = TFormedY()
			xz# = TFormedZ()
			TFormVector 0,-p\size,0,Camera, 0
			yx# = TFormedX()
			yy# = TFormedY()
			yz# = TFormedZ()
			For l= 0 To 3
				u# = u2 * ( l=1 Or l=2 ) + u1*( l = 0 Or l = 3 )
				v# = v2 * ( l > 1 ) + v1 * ( l < 2 )
				mx# = ( l > 1 ) - ( l < 2 )
				my# = ( l > 0 And l < 3 ) - ( l=0 Or l = 3 )
				x# = p\Position\x + xx * mx + yx * my
				y# = p\Position\y + xy * mx + yy * my
				z# = p\Position\z + xz * mx + yz * my
				VertexCoords s , p\Vertex+l , x, y, z
				VertexTexCoords  s, p\Vertex+l , u , v
				VertexColor s , p\Vertex + l , p\r,p\g,p\b, p\Life
			Next
		EndIf
		
	Next

End Function