pbr rayswitch

[mattvfx]

is there any way of doing a rayswitch in pbr?

there is a thread that contains some examples of rayswitch but only works with raytrace

thank you in advance

[dennis.albus]

I know I am quite late to the party, but I just had to deal with this problem myself and luckily found a solution  . It works for both PBR and Raytracing (when using the pbrlighting nodes or compute lighting).
It uses some undocumented ray labels that you can import into your shader. Those can be found in pbrlighting.vfl. Always worthwhile to skim through those source files and discover something new.
 

$HFS/houdini/vex/Surface/pbrlighting.vfl    (line 227-237)

if (trace(hitP, hitI, hitTime,
	"SID", path_sid,
	"angle", filter_angle,
	"ray:length", hitLength,
	"Cf", hitLight,
	"Ce", hitEmission,
	"send:diffuselevel", dlevel,
	"send:reflectlevel", rlevel,
	"send:refractlevel", tlevel,
	"send:volumelevel", vlevel,
	"send:pathstate", pathstate))

rayswitch.hip

[dennis.albus]

This version works even better. This code is used to switch between the different labels:

int pathstate;
string label;

rayimport("pathstate", pathstate);
label = bouncelabel(pathstate);

if (getraylevel() == 0) { ray = 0;} // primary visibility
else if (label == "reflect") { ray = 1;}
else if (label == "refract") { ray = 2;}
else if (label == "diffuse") { ray = 3;}

rayswitch_improved.hip

Edited November 28, 2014 by dennis.albus

[glassman3d]

amazing thanks!

 

been trying to get refracted IDs working for ages in pbr

[tricecold]

hi there;

 

not so related maybe but I have a question. I have a single object with a ramp lets say as Cd attribute, black to white. its a glass object and has two spheres behind it red and green. Would it be possible to tell to shader to rfract and relect white areas for object 1 only and black areas for object 2.