Sun question?

[Shopper2]

Hi guys,

Is it possible to have a background HDRI map in use when using the sun and sky?

I would like to have reflections in my chrome when using the sun.

It seems only to work when i turn the real camera off (but then the sun goes wild)

Also is it possible to create blurry shadows with the sun......there seems to be no radius setting there?

Thanx so much for your help again!

Justin

[dalomar_cg]

Re: Sun question?

Yes it is possible. First of all your going to need to increase the intensity of your hdr allot. How much will depend on the intensity of your HDR and the exposure in your scene, but keep increasing it and it will show up. If you want you can map that simply to the background in the Environment rollout. Or you can leave the sky in the background and put the HDR in the reflection slot. You can also do this in the material itself as well.

As for blurry shadows from the sun your going to increase the sun size. I usually go around 15 which should work.

[bdcali_cg]

Re: Sun question?

VfR 3/SR1 doesn't have a size option:
The directional light shown was placed using the "Sunlight" command.



Image from Vray manual:

[joe_b]

Re: Sun question?

The second screenshot is from VfR 4? That is how it should look...I suppose maybe the RDK fires off different messages in Rhino 3 than 4, so maybe we're not reacting properly. I'll have to look into that further.

[bdcali_cg]

Re: Sun question?

I'm not sure if the second image is coming from VfR 4 or VfR3... I copied it from the PDF manual.

[dalomar_cg]

Re: Sun question?

That would be V4.

[Shopper2]

Re: Sun question?

Hi Guys,

Im having a bit of trouble seeing reflections from my background image on my chrome product using the sun. Im using a still camera....shutter speed 400, f12, iso 200 and the lighting is fine. In the background slot i got an hdr map, but it just doesnt show up when i render. I have tried the common multiplier from 1 to 100 but no go. I also tried dropping it in th ereflection slot but also no go. I treid selecting the chrome material and placing it in the background map under options....also no go. What am i doing wrong? It seems to be something with the camera? (since it works when i turn it off...but the sun goes mad)

Thanx

Justin

[Micha_cg]

Re: Sun question?

Try higher values than 100.

[Shopper2]

Re: Sun question?

Hi,

Ive tried values of 200 and higher...nothing.

Also if you put the reflections on the material itself it should come up on standard values such as 1 right.

Could anybody make a file for me with a GI Sky and a physical camera with an HDRI background and a chrome ball on a floor? That would help heaps......but to me its looking like a bug?

Thanx


Justin

[Micha_cg]

Re: Sun question?

... also 10000 or 100000?

[dalomar_cg]

Re: Sun question?

Its not a bug...The actual amount that you will need to increase the HDR is dependant on two things; the exposure for your scene, and the intensity of your HDR. The V-Ray sun is about the brightest object that you can have in a scene, there for the exposure is going to be very low in order to manage all of that light. If you have a regular image (jpg,png, or what have you), then you will need to increase the multiplier on that significantly. Although a value like 2000 seams like allot, its only twice as bright as a value of 1000, so the amount you will have to increase the multiplier is an exponential relationship not a linear one. Hope that explains a bit of whats going on.