question concerning rendering metal and granite

question concerning rendering metal and granite

so, I am trying to render a gold plated object that is sitting on a piece of black granite. Of course, I want to see the reflection of the gold object on the granite's surface.

I am using a HDR that I made in photoshop, basically just a cloud filter with grey and orange as my two colors.

My problem is this. To get the reflection of the gold onto the black granite, I need to crank the reflection intensity up. This causes the granite to look orange (reflecting the hdr) instead of black. If I darken up the reflection color of the granite, then I get lots of ugly black reflections showing up on the gold object.

And I really want to add some blue velvet drapes behind the objects, but this not only puts a lot of unwanted color onto the gold object, but it also blocks out a lot of the hdr light.

The drapes have a render tag that allows only primary rays and radiosity.

I am using ambient occlusion.

Any ideas on how I should go about this?

I am attaching a bunch of screen shots as a zip file for all to look at.

Thanks a lot! I really appreciate the time and suggestions.

Cheers, Chuck

Could you please just attach the images to your post? I'd prefer to avoid downloading, unzipping, viewing, then tossing out images if I can help it.

I was trying to not clutter up the forum with a bunch of less than stellar images, but here they are (sorry about the nasty jpeg artifacts)


Cheers, Chuck

I'd change the HDR to be less colorful and try fresnel on the granite. If you want an orange background -- handle that separately.

You could also try changing the reflection color to blue (since that will treat orange as black).

Thanks for the suggestions!.

I ended up going with a different HDRI, which definitely helped me get the granite looking better, though still not black, but at least it isn't orange.

I never even thought of checking fresnel, as neither object has any transparency. It seems to make the reflection on the granite a little bit more enticing, though the difference is subtle.

I ended up scrapping the idea of using drapes. I figured that using HDRI to light the gold was more important than not using an HDRI at all, to allow me to place the drapes around the object.

The reflection color that ended up working the best was more of a dark mauve. I also cranked up the reflection angle, which seemed to make it look a little bit more realistic.

Thanks for the help, Pod.

I will post some screen shots once the 8 second animation is finished exporting. 1x1, 8x8, 2056 x 1440, 240 frames, looks like it is going to take 37 hours on my 3.2ghz, 8 core, mac pro! It's a good thing I have a fast computer. :smile:

Cheers, Chuck