vray light or direct light for sun

[tricky]

Are there any advantages in using a spherical vray light over a direct light for the sun in external images? Which is the best option? Any opinion?

[vlado]

A direct light (possibly with area shadows) would be best.

Best regards,
Vlado

[tricky]

Could you explain why? I assume its because a spherical light emits in all directions, therefore it would be slower. I just wondered if the Vray algorithms were perhaps faster than a standard Max direct light's.

[Da_elf]

this was the very same thing i was saying in the announcement section

[percydaman]

heres a test I performed: DIRECT LIGHT







VRAY LIGHT



As you can see, the rendertime is about the same, but the two images look different. First of all, even though I turned off Decay on the vraylight, it still appears to do just that. The effect is a little bit exaggerated since the vraylight is kinda close to the scene, but the effect is there nonetheless. Also, on the teapots, you can see shading errors with the vraylight that dont appear with the direct light.

All in all, I would also suggest using a direct light.

P.S. The vraylight appears just a tad faster in this scene, but was slower in the scene if there were fewer teapots. So maybe the vraylight is more efficent at higher polycounts?

[nvanherpt]

it's mildly disturbing seeing that many teapots

[jacksc02]

good test there Percy.
I have started using spherical vray lights as the "sun"
I like the quality of light better, sure you have to give it a few more subdivisions but i think its worth it.

[Da_elf]

the direct light one looks more natural to me.

[R2J2]

you need to use direct for the sun because even though it sends out light from all directions, the sun is so big and so far away that when the light rays hit earth they are parallel to each other (pritty much)

[mikeeee2]

Use a spherical light 1.4 mil km in dia about 150 mil km from your model and that should get the calculation about right. But you might have to turn the subdivisions WAYup.

[cpnichols]

Artistictly speaking, I like what the area lights do better. I also like the reflect/spec you get from it better. But we have already had this discussion. Ultimatly, I think these issues can be different on a shot by shot bases. It may be that so many movies are done with faked Sunlight on set, that that look is appealing to me. This is especially true with sun coming through windows. We I was on set, I was always so amazed that they get a shot where it looks like it is 9 am with the sun coming through the window, when in fact it is 10pm and there is a big 8k light 30 feet outside. Looks very real... in fact, I would say, it looks more real than sunlight.

[tricky]

Direct light seems the way forward - thanks for the info.
Maybe Vray could have a specific sunlight in a future edition.

[RErender]

Direct light seems the way forward - thanks for the info.
Maybe Vray could have a specific sunlight in a future edition.

I believe it is implemented in the soon to be released sun /sky system, don't quote me though