i need shading the surface of the water, how can i keep the water's color?
attached pic show's my problem,all three pics are shaded with houdini's default glass shader.

the first one's refraction attenuation is nice,but the color goes black

the second one, i add diffuse to the water,but it seems never opacity.

the third one is what i like, i add a blue volume under the water to let it refract the right color , but it's very slow, how can i add this color to the shader?

You can fetch the ray distance with a gather function (or gather vop), and fit the range, then control the interpolation with a color ramp parameter to have artistic control.

alejandro
You can fetch the ray distance with a gather function (or gather vop), and fit the range, then control the interpolation with a color ramp parameter to have artistic control.

thank you alejandro, i have understand your advise. but can you make a simple vop example? i don't know how to get the ray distance. and not fully understand gather vop(i once saw one gather vop example, it add a constant value 0, don't know why ).

Look at this post.

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=23300 [sidefx.com]

But this file has the ramp example.

alejandro
Look at this post.

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=23300 [sidefx.com]

But this file has the ramp example.

nice! thank you very much alejandro