Understand Houdini's (heightfield) remap operation

Houdini Of SOP There are a large number of nodes Remap operation , Literally translated as " Remap ", The effect is through Y-X Function curve to remap . A typical node  heightfield_remap

You can see the following example HeightField-Flow-Filed obtain flow chart

then flow Value range is not in 0-1 Between , We are going to do a function mapping remap, hold flow The entire range is mapped to 0-1, Facilitate the use of other software

You can see flow The data of layer is in 0-21.82 (x Range ) Between , Mapping to 0-1 Between , Just use y = 0.05 Function of ( Roughly estimate ),

That is, the function curve in the graph .

 

  What's more important here is Horizontal is Y Axis , Vertical is X Axis , So the above function curve is  y = 0.052x, Or you can just take the position of the subscript as the slope .

Because the second point in the figure above (0.052,0) End point , There is only one curve , The whole transformation curve is y = 0.052x Relationship .

Visualization results ：

 

  hypothesis remap Multiple points are multi segment functions , As below :

  Look at the values of three points

  The first function x1 = (0 ~ 0.0557 * 21), y1 = 0.0557 * x1;. Second segment function x2 = (0.0557 * 21 ~ 21), y2 = -0.195 * x2.