Noise!! where is it coming from??

[sleipnir]

Hi people!!

I'm new in the forum and also a quite new Vray user.

I'd appreciate some help and some advices to improve my work

The image I'm attaching is unfinished and scaled down but is enough to see the problem: Those black spots on the round columns

I can't get rid of them, although I keep rising the quality settings.

The two round columns have different materials, both with 22 subdiv for reflection and refraction, all the lights in the scene have 30 subdiv for their shadows.

I'm posting the settings I'm using.

I've tried to use LC as secondary GI but the render times skyrocketed, I could never make it to the end of the light cache build up.

Now the rendering is taking about 24 hs in a Core2 6400 2.13 Ghz, and even though the resolution is high (3000x1800) I suspect that this scene could be rendered faster with less quality settings and without noise.....

 

I will very much appreciate your help

 

The advice part is about how the scene is lighted, I've tried to used just one direct light as a sun but it wasn't enough so I added Vray lights on the windows and also a dimmed one behind. Is there a more realistic and efficient way to do it? suggestions welcomed.

 

Seasons Greetings for all

 

Diego

[lambros]

The first thing I could point out is the min subdivisions of your AA, they are too much. with a minimum of 3 you are forcing vray to use more samples in places that they are not needed.

Also, if you are using Evermotion models, keep in mind that most of them have a top poly count and their materials often have killer subdivisions. Perhaps you could try optimizing them to lower your render times.

I use LC for secondary, most interior renders at 3K do no more than 2-3 hours on a dual core on the worst case.

Hope this can help a bit.

 

Oh and note that you could include vray lights in the irradiance map to get smoother shadow results

[viz.k]

It's actually not noise what you're showing. It's just bad quality caused by low QMC subdivs value. I don't generally use qmc but if you do, increase this value to 30 or even more...it takes long to render so my advice would be to use light cache/irradiance map. I nearly always do that.

 

Also try decreasing noise threshold and adaptive amout, but it will not help you because my opinion is that there is no noise on this picture:)

[sleipnir]

Hi Guys!,

Thank you very much for your answers.

Both of you were right to point to Light Cache

Lambros, you were right about evermotion materials, i've found some materials with 50 sdiv and even 80. I lowered most of them to 8 except the few ones that are noticeable for they reflections and close to the camera which I put in 25. I've checked "store with irradiance map" on the lights and I carried the sampler sdiv to 2/5.

Finally I rendered with IM+LC in low res (800x480), it took 51 min and the result looks pretty good.

I'll see what happens with full res regarding LC times.

 

thanks again

DIEGO