Reflections

[snailfish]

Hi all,

can't figure this one out;

I have a hemisphere with a HDRi. I have two animated spheres on a ground plane. I want these three objects to reflect each other and get the reflections form the HDRi.

Any help appreciated

[TheUsualAlex]

Hi all,

can't figure this one out;

I have a hemisphere with a HDRi. I have two animated spheres on a ground plane. I want these three objects to reflect each other and get the reflections form the HDRi.

Any help appreciated

Hmm... have you converted the HDR image to Houdini's native .rat format via an external utility called iconvert? I am not sure which of the default shaders shipped with Houdini that'd let you do it tho... so you might have to check and see... Most likely you'll probably have to roll your own shader through VEX/VOP...

[Jason]

Hi there,

You can do this, yes indeed. Unfortunately, as Alex correctly surmised, the Reflected Light VOP doesn't have the parameters exposed that you need to do this. And also, none of the shipped pre-made shaders support this either.

If you're comfortable with writing shaders in VEX proper, this is what you needs to know:

Use the reflectlight() VEX call : http://www.sidefx.com/docs/content/vex/fun...eflectlight.xml

And look under the Optional Rendering Parameters for all these variadic VEX functions: http://www.sidefx.com/docs/content/vex/gui...ing_rayopts.xml

So, by way of example, the code snippet you might want is something like this:

  reflection = reflectlight( P, N, I, bias, max_contrib, "environment", "/path/to/HDR.rat");

If you're not into writing VEX native code, I'd suggest making your own copy of the distributed Reflected Light VOP and adding in support for the "environment" variadic argument yourself. This is not hard to do, except for the first time you do it

Unfortunately VOPs are not quite complete enough these days... SESI have added a lot of functionality to VEX and are yet to upgrade VOPs to take advantage of all of these.

I hope this helps. If you get stuck, please write again:)

Jason

[edward]

Doesn't the default VEX Metal SHOP have an environment map parameter? Sorry, I'm too lazy to open houdini right now.

[Jason]

Doesn't the default VEX Metal SHOP have an environment map parameter? Sorry, I'm too lazy to open houdini right now.

Oh gosh, you're absolutely right. It does

[snailfish]

Hi.

thanks for the quick replies.

I'll have a go again later today with these new inputs

There might be some new questions here...

thanks for helping out.