I am experimenting with the shadow catcher feature of Carrara 4 Pro. Has anyone evr hot this to work with HDRI lighting? If I place a spot light the shadow catcher feature works ok but if I use an hdri image and remove the spot there is no shadow. I can't use the spot as well as the shadow cast by it is not as realistic as that with hdri.

Message edited on: 09/08/2005 02:59

Attached Link: Shaders Plus on Digital Carvers Guild site

Somebody once explained to me why it is impossible to do 'shadowcatching' this way, because there is no shadow to be catched in HDRI lighting. Just 'less light' to be shown. And you can't show something that is not there, can' you? Well. It sounded logical then. But. Enter Eric Winemiller: Shaders Plus has a GI Shadow Catcher feature. And much more that comes in handy by the way.

Hey, thanks for the quick response and explaination - I'll go check out your link. Many thanks

No plugin was used here in this Carrara Pro 4 render. Make sure you have a distant light in your scene so that shadow catching works with a HDRI background. Skylight illumination was used to provide nearly all the lighting from the HDRI image. Any other lights were at 1 - 50% brightness. Global Illumination was turned off.

Here is a more realistic one using decreased shadow strength and an increased light radius around the shadow.

Here is the shader used for the infinite plane.

EXCELLENT Shonner!!! This is exactly what I was looking for. I knew there must have been some way to simulate this - just couldn't figure out how. I am soooo impresse with Carrara - the quality of the rendering is amazing. I sure hope more people post their work here at renderosity - the gallery looks a bit sparse (surely you have some good renders Shonner?)

Here's another one. No plugins used.

stealth1701, I put a render in my gallery if you want to see what I've been working on.

SHONNER, Hmmm, I think Im missing something. I set up the shader for my plane exactly as you had it in the image but for some reason it renders the plane as black. Any ideas? p.s. where did you get your hdri images??

The key is to insert a distant light in your scene. The shadows will be caught by the plane you're using. My distant light is set at 50% brightness with soft shadows turned on for it. The HDR file is in the C:EoviaCarrara 4 ProScencesGlobal Illumination folder on my PC.

Here is a hubcap made with Amapi Pro 7.51 rendered the same way.

Oh... and turn off ambient lighting (0% brightness).

Here are the render settings. My skylight is set at 200 so that the horizon line from the inifinite plane isn't seen.

Message edited on: 09/10/2005 17:15

Pay no attention to the guy in the bright outfit. He still has a default shader that hasn't been textured properly for the scene.

This scene was rendered using the Shaders Plus plugin from Digital Carvers Guild. Its Global Illumination shadow catcher which I used for my infinite plane works with Global Illumination turned on in the render settings and doesn't require the use of distant lights.

Actually I think the original without the plugins is just as good so no point in spending $29 when it can be done equally well as you have shown above. Thanks for this insight

I disagree stealth. THere is a highlight on the globe, (that is probably from the distant light,) that isn't in the other scene. I prefer the 2nd one myself. :D Besides, there are so many other good things in the Shaders Plus plugin, that the GI Shadow Catcher is just one of. My 2 cents....