image planes , reflection and PBR

[infinity_spiral]

I have a some problems here to get reflection to work and I need your help.Please excuse my English.

First I am trying to figure out why when I use Environment light with HDR image I don't get the reflection on material such a "silver material" when using micropolygon or raytrace render .I am getting the reflection only when PBR is used.I know about the ability to apply env map inside the material but the question is what is difference between raytrace and PBR render when PBR uses raytracing to calculate the reflection, and why env light with hdr image doesn't work when raytrace is used.

Second question is related with the image planes.I am trying to output the reflection as a separate image plane (channel) But I don't get anything in a render.I am using again the silver material from the material library and env map applied to the shader. I am able to get the diffuse, specular but reflection just doesn't work. Basically what I am doing is I am adding a variables like "reflExport" ," specularExport" in the image plane .This variables are created by default inside the shader What I am doing wrong that I can't get only the reflection.

And the third question is why I can't have image planes when PBR is used?Is this limitation with PBR or I have to have special shader for that?

I hope my questions are clear considering my English.

Thanks

PS I am using Houdini 9.5.350 HD