domingo, 28 de abril de 2013

sexta-feira, 26 de abril de 2013

Multiple objects in copy SOP houdini

From houdini 12.5 help about copySop:


create a switch node and a copy sop

in copy sop turn on Stamp inputs
and create a Variable1 = switch  -----> value1 = fit01(rand($PT),0,(opninputs("../switch1")))


in switch node insert expression connecting the stamp variable :
stamp("./copy1","switch",0)

quinta-feira, 25 de abril de 2013

Move Points along normal HOUDINI


From :  http://forums.odforce.net/index.php?/topic/15659-move-geometry-along-a-point-normal/

peak SOP is your friend.  It transforms the point along the point N, or you can use a point SOP and do a $TX + ($NX * 0.1),  $TY + ($NY * 0.1),  $TZ + ($NZ * 0.1) in the position paramter.  The 0.1 value is the amount you want to move it along the normal.  That expression is doing what the peak SOP does. 

randomiza normals HOUDINI


From http://www.3daet.com/pages/764/random_normal_rotations/
A great way to randomize normals without copy stamping geometry.

Save memory and randomize normals without stamping geometry.


Date Created:Friday March 16th, 2007 01:58 PM

Date Modified:Sunday August 03rd, 2008 09:30 AM
Lay down a grid, and append a point SOP. Use these values for the Position parameter.
TX: $TX+noise($TX*5,$TY*5,$TZ*5)*3
TY: $TY
TZ: $TZ+noise($TX,$TY,$TZ)*2
Toggle on "Add Normal", and set the values to 0 0 1
Append another point SOP, and toggle on "Add Normal". Use these values:
NX: $NX+fit01(rand($PT+1.001),-1,1)
NY: $NY
NZ: $NX+fit01(rand($PT+1000.001),-1,1)
Go to the particle tab, and toggle on "Add Up Vector". Use the values 0 1 0.

terça-feira, 23 de abril de 2013

rand() entre numeros positivos e negativos !

Formula Basica para criar um numero randomico entre valores positivos e negativos
eh :
-min + (rand() * ((max - (-min)) + 1));