Light & material questions

[c4d-Jack]

Hi,

I got two questions.

1. Spot light: Decay
When I set a spotlight to "inverse square" decay, the decay length of the lightsource is set fixed to 1000 units. Where can I change this length? there must be some possitility, because some lightsources may be further away from the scene than 1000 units.

2. Anisotropic speculars
How can I do these radial speculars, like shown in the following example (Rendered in AdvancedRender)?
http://www.c4d-jack.de/darkside/vray/metall_test_1_ar.jpg

Thanks for any tipps!

Greetings,
Jack

[DanieleF]

Hi Jack,
the decay length does not matter for vray, is fixed at 1 meter for give you this evidence. So don't worry abut that.

for the anisotropic specular try changing the anisotropic axis and anisotropic rotation

Cheers
Daniele

[c4d-Jack]

Hi,

thanks for the quick answer.
Hmm...

the decay length does not matter for vray, is fixed at 1 meter for give you this evidence. So don't worry abut that.
But e.g. my lightsource is about 2000 units away from the object I want to light. When inverse square decay is selected, the object does not recieve any light at all. What should I do? Moving the lightsource nearer to the object of course changes all shadows, so I don't want to move it.

for the anisotropic specular try changing the anisotropic axis and anisotropic rotation
I already did. But it seems 'Anisotropic rotation' just rotates the direction of the anisotropy, but doesn't bend it to be radial. Is there a demo scene that shows something like the material I used in the image above?

Thanks ;-)

Greetings,
Jack

[stefan]

in realworld there is not decay distance.

how far the light travels is only controlled by the strength of the light.
same is in vray when you use realistic decay.

cheers
stefan

[stefan]

for the brushed metall i would use a small bump texture combined with reflections anisotropy.
you can also use lumas, but only without the physical camera at the moment.
(we try to make that work with phycam too)

cheers
stefan

[c4d-Jack]

OK, then I'll try bump.
Thanks, Stefan :)