topic Re: Pixelated image in VRED Forum

Pixelated image

Anonymous — Tue, 08 May 2018 13:44:17 GMT

Hi guys...

Perhaps I'm missing something...

I try to render some interior images, and even after 22h or 40h rendering a image, still get a lot of pixels into my image.

I already check all option, but I can't find nothing to change to create a good quality image.

If you guys have some recommendations i will be very appreciated.

Re: Pixelated image

richardlevene — Tue, 08 May 2018 14:19:47 GMT

Can you share the image so we can see what you mean exactly by pixelated? Or even just a region of the image (so there are no distinguishable features if it is a sensitive image)

Is it noise in shadow areas or is it edges not looking smooth?

Are you rendering with raytracing? Are you using Full Global Illumination?

Best,

Richard

Re: Pixelated image

michael_nikelsky — Tue, 08 May 2018 18:42:22 GMT

An image would be good. However there are twothings that can cause eccessive noise:
1. Lights behind glass: These lightsources are pretty much invisible to the path tracer and can only be hit by accident. The illumination you get here a basically caustics and the only way to do these efficiently is by using the photon mapper.

2. Reflections of lightsources in chrome: This is pretty much the same situation as the glass since you are getting caustics again. Again, photon mapping should help here

And the worst case of all these are acually reflections of caustics. A path tracer can not handle these without tracing hundreds of thousands of samples. Again, photonmapping can help you here again.

The drawback of photonmapping is that it will introduce bias and it does not work well with large scale models (like a factory or something like that). It also requires some additional setup to get right and efficient.

But as Richard already said: An image would be very helpfull.

Kind regards

Michael

Re: Pixelated image

Anonymous — Tue, 08 May 2018 19:47:33 GMT

Hi guys, thanks for reply @richardlevene @michael_nikelsky

Is a sensitive image, i can show just the part that i get problems:

Too much noise in this surface.

I will try to get all the configuration in Render settings.

Re: Pixelated image

richardlevene — Tue, 08 May 2018 21:32:05 GMT

Hmm that is really hard to tell from that image. It doesn't look as noisy as I was expecting.

What size are you rendering at?

Are all the materials on your car properly prepped? What is that blue material?

Do you have any objects with incandescence on?

For some of the things Michael mentions, for interiors we typically render with all glass turned off (then do a separate render for the glass and the glass reflection) also if you are rendering with Full GI, then limit the number of bounces down to 2 or 3. This is controlled with trace depth. So try bringing that down to 3. You might get less bounce light but it can help with the noise.

What I would like to see in vred is the adaptive dome light optimization that vray have integrated into their domelight to help with interior shots like this. Or have the portal lights support raytracing (like they have in arnold)

Curious on the devs thoughts on the above.

In the time being the other thing you can do is kind of cheat like people have been doing for a long time and place in extra lighs that act as your extra GI bounce inside the interior. Turn off the lights primary visibility and make sure it is not visible in reflections or refractions. So it is just to help for your diffuse bounce.

Best,

Richard

Re: Pixelated image

Anonymous — Wed, 16 May 2018 13:24:58 GMT

You can increase the Antialiasting > Use Image Samples, though it will increase your render time. If you have Pro, you can try turning on the Denoise Filter.

Re: Pixelated image

Anonymous — Wed, 16 May 2018 13:38:00 GMT

Hi guys, thanks a lot for all help, I just discovery all settings are basic:

1234

I will try to use some other options and try to tune some others like you guys told me.

Son I can get, o will post some results here.

Thanks!!