V-Ray Sun questions

[brijcharan]

Hi there.

I'm doing an interior rendering tutorial with v-ray in 3dsmax, where the author uses the sun in 3dsmax, but I was able to use the trial to convert the scene to fbx and load in modo fine.

In the tutorial, the author uses a sun light in 3dsmax, so I used:

• Modo direct light
• Enabled Physical sun
• Added V-ray Sun/Sky

So a few questions:

1. Now one thing she does in her tutorial is add a VrayHDRI in 3dsMax.
   I don't see this anywhere in v-ray for modo, so I'm assuming we use the regular modo environments?
2. What are the settings for using image-based hdri for modo environments when working with V-Ray Sun/Sky?
3. With the Environment material (not image based), I switched it to use Physically-based Daylight, as the environment type, and used my direct light as my Sun. It seems to work, is this correct?
4. Should I 'Clamp Sky Brightness' in the Environment Material?
5. The environment has its own 'intensity' value, and the sun/sky v-ray addon also has its own intensity multiplier.
   Which should I use?
6. To increase the shadow blur, I used what I do in photography, I increased the light size to soften shadows, or in this case the sun size. This seemed to be most 'real world' way of softening the shadows. Is there another method that is more recommended?
7. Are there any v-ray specific ways to make sure the Modo Shadow catcher works correctly? It seems to work, but not perfectly. (see attached image)
   

I really love how beautiful the shadows look coming from the sun, I'm not sure if this is v-ray rendering those so nicely, or modo helping, or both. But awesome either way.

Thank you!

[Muhammed_Hamed]

so I'm assuming we use the regular modo environments?

Yup. Just make sure importance sampling is enabled in the GI tab. Also you can use a Vray dome light and enable Dome spherical. Then in the shader tree you can assign the HDRI. Make sure the mapping is set to spherical in Y axis.
Both methods should give you the same results.

What are the settings for using image-based hdri for modo environments when working with V-Ray Sun/Sky?

You cannot use both methods together. Only use one of them to light your scene. Do you have a link to the tutorial so that I see what she was trying to do?
See here for more details on Vray sun and sky,
https://www.youtube.com/watch?v=IF2rSoeEbPc

It seems to work, is this correct?

Yeah..that is how it works.

Which should I use?

Use the sun multiplier or the physical camera to control intensity. That is how I work with it. I use the environment intensity when using an HDRI.

Is there another method that is more recommended?

Not sure really,but for me I use Image based lighting all the time and I have 32 bit controls in Photoshop or HDRI light studio. So I can soften the shadows really easily.

It seems to work, but not perfectly

I didn't have any problems with it. No idea why your shadow is cut off. I think it would be better to post the scene and screenshot in the problems section.

I really love how beautiful the shadows look coming from the sun

It is the power of Vray . Vray sun and sky is one aspect that people underestimate and barely use(Including me lol) I should experiment with it and use it more often.