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mitchino
06-10-2010, 12:32 PM
I'm having a lot of trouble understanding how GI and specularity work together. I'm trying to do a studio render of a product, and I'm using HDR Lightkit Pro. I like the overall look of the shot, but in real life the label has specularity that I can't seem to achieve, I'd like a nice highlight down the left hand corner.

Is the best way to forget about specular settings and use reflection - i.e. drop in some reflector planes that only affect the label?

Any tips gratefully received - WIP attached.

mitchino
06-10-2010, 12:44 PM
I'm looking for something more like the plastic top in this render.

Katachi
06-10-2010, 01:16 PM
Is the best way to forget about specular settings and use reflection

In real life it has reflections (specularity IS reflection, but the specular material effect is just a handy "fake"), so the answer is yes use reflection or add the specular pass in post to the image.

mayajunky
06-10-2010, 02:32 PM
You could also add a key light, with the light linked to just to the label to help you achieve that sharper specular.

brasco
06-10-2010, 02:39 PM
The specular channel is dependant on having cinema lights in the scene to generate.

To get similar highlights to the second image, look into using reflection channel, to make the reflections more diffuse, up the bluriness (and AA to get a smoother blur).

for clartiy:
Specular Reflection (http://en.wikipedia.org/wiki/Specular_reflection)
Diffuse Reflection (http://en.wikipedia.org/wiki/Diffuse_reflection)

hth

brasc

mitchino
06-10-2010, 03:13 PM
aha. I was thinking that I would need c4d lights to get the specular - what I can't figure out is that with the HDRI Lightkit Pro studio scenes, whenever I try to add a light, it appears with a red x and I can't turn it on. The setups have a global lightswitch at the bottom of the object stack that prevents c4d lights from working. Need to read the manual for lightkit pro.

Meanwhile getting somewhere with reflective panels providing a specular.

lewisrowe
06-11-2010, 11:27 AM
what I can't figure out is that with the HDRI Lightkit Pro studio scenes, whenever I try to add a light, it appears with a red x and I can't turn it on. The setups have a global lightswitch at the bottom of the object stack that prevents c4d lights from working. Need to read the manual for lightkit pro.
how about copy/paste an existing LightkitPro light and edit that.

lewisrowe
06-11-2010, 11:41 AM
I'm looking for something more like the plastic top in this render.
or..
how about put a luminance grad on a fairly big plane. then select that plane, select lighting tool (with mode set to specular placement and 'modify lights only' not ticked), then click on your model where you want the specular highlight to land and lighting tool will position the luminance grad perfectly for you. then adjust the size of plane and style of grad to suit.

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06-11-2010, 11:41 AM
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