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As mentioned in the title of this post I am just struggling with the noise in my render result. I am not talking about fireflies, I am talking about actual noise.

I read a lot about how to improve the result by increasing the amount of samples and stuff, but for the following result I already sampled the image 2500 times.

enter image description here

As you can see, the scene is quite simple. I modelled a room with multiple spotlights in the ceiling.

enter image description here

In full resolution I have a lot of noise in the darker areas, even after 2500 samples.

The target of the project is to make 3-5 sec camera animations, that lead from one hot spot in one room to another (the showroom isn't finished yet btw).

This image took me about 12 minutes to render on renderstreet. And regarding the finished project, it would take me about 74 hours to render only one animation with this noisy result.

So my question is, how can I get a cleaner result with less samples, so it will render faster?

I added my .blend file for you to download. I deleted the glass stuff in the middle of the room because I want my client to be anonymous).

http://www.file-upload.net/download-9405390/main.blend.html

Thanks in advance! -Marten

Marten Zander
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  • possible duplicate of How to avoid noisy renders in Cycles? – Ray Mairlot Aug 20 '14 at 12:02
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    @RayMairlot I know that post, but as I said I am not looking for the answer to simply increase the number of samples. I already had a total amount of 2500 samples per pixel wich is pretty much I guess. Even though everything above doesn't really improve the result anymore, its just pushing pixels arround but not making it smooth. – Marten Zander Aug 20 '14 at 12:08
  • Try these https://www.youtube.com/watch?v=kE7kh5WdE3k , http://wiki.blender.org/index.php/Dev:2.6/Source/Render/Cycles/ReducingNoise and http://www.blenderguru.com/articles/7-ways-get-rid-fireflies/#.U_SSn_ldVRo – someonewithpc Aug 20 '14 at 12:20
  • @someonewithpc Yeah I know most of the tricks, such as activating "no caustics" and and "clamping". I guess my problem might be the small light sources. The light in the scene is only emitted by the holes in the ceiling plus additional spotlights at the same position for each hole. I will give a shot at the first video you mentioned. Maybe I can fix my noises with his compositing solution. – Marten Zander Aug 20 '14 at 12:34
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    Perhaps change the title to "Reducing noise in interiors caused by many lights" to avoid this question being closed. – Greg Zaal Aug 20 '14 at 13:24
  • Related: http://blender.stackexchange.com/q/10434/599 – gandalf3 Aug 20 '14 at 20:04
  • @gandalf3 actually its not related to what you posted since i don't use glasses surrounding my emitting meshes. – Marten Zander Aug 21 '14 at 07:12
  • I had a go at optimizing it, and got this image rendered in 16:53 on my CPU (quad core xeon) with 100 samples. It's not great, considering the resolution and the denoising which may be unstable in animation (I haven't tested it), but hopefully it'll give you some ideas.. If nothing is moving except the camera in the animation, then you can also try baking any shading which isn't dependent on the camera angle (e.i. diffuse). If possible, cutting back on the number of lamps will also help. .blend. – gandalf3 Aug 21 '14 at 07:19
  • In your example render the lighting is so even you might want to consider relying almost entirely on AO, and just using a few lamps in the sockets next to the pictures etc. – gandalf3 Aug 21 '14 at 07:23
  • @gandalf3 first thanks for your effort, it's much appreciated! In the meanwhile i also found this awesome noise reducing node group, it does a great job and also saves me some extra samples. I didn't try it on animations yet, but i hope it works otherwise I can't make use of it in this case:/. With the glass/glossy materials you mean the small windows infront of the pictures right? Well that seems to be legit, I misunderstood that. – Marten Zander Aug 21 '14 at 08:18
  • @gandalf3 btw, what do you mean with just using ambient occlusion to light the scene? you mean setting light paths to direct light and activate ambient occlusion? – Marten Zander Aug 21 '14 at 14:03
  • @SlimMarten That could work to, but I meant only using a few lamps in places near the pictures, where they are aimed at the wall. The main thing which I think is hurting performance here is the number of lamps.. – gandalf3 Aug 21 '14 at 20:37
  • Did you find any solution to your problem? I have a similar problem... – Max Kielland Oct 30 '14 at 01:00
  • @MaxKielland Hey dude, I actually did! I am just in a hurry so I will write a response later. For now I can tell you, my solution is "linear workflow" .. I will write down more details later, but you can already google it, it's kinda hard to understand and it takes some time until, you realize how it actually works.. – Marten Zander Oct 31 '14 at 07:46
  • Thank you, I googled it and there are a lot of material to read on the subject. I managed to fix the most of my problems but still have some noise in glass materials with a light behind them. – Max Kielland Oct 31 '14 at 12:22
  • @MaxKielland what kind of light to you have behind it? ..Glass materials need much more smaples to render clearly than normal diffuse materials. Maybe try increasing your samples for glass. – Marten Zander Nov 03 '14 at 08:15
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    If the lighting is going to be static, you can consider baking all the light and texture information into a texture, and then just run the camera through it. – Mike Pan Dec 05 '14 at 19:20

2 Answers2

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I guess, that you know most of the common tricks. But here are some tricks that I often use:

  • Make a hole into the building outside of the cameras view of field
  • Increase the resolution, decrease the sample rate and resize the image afterwards. This will make the image softer, but if you double the image size, and render with a low sample rate and resize the image afterwards, the noise is evened out (I was able to render an interior architectural scene with only 5 samples)
  • Enable a small amount of global illumination and increase the shadows afterwards with the Compositor
p2or
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frameworker
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  • Increasing the resolution works fine for noise problems, but also has some downsides: the render will take much more memory and might be slower in total. A picture at 200% render size may take 1/4th of the samples, but more than 4x the time to render. – piegames Sep 13 '16 at 15:16
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Did you bake your lighting? If the only thing that is moving is camera and not the lighting or the objects, you can bake all of that data to textures, apply them to each object and you can practically render and view your scene in realtime.

jay
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    Welcome to the site :) Here we like detailed answers which explain how to do things in addition to general tips. If you don't wish to spend time on a slightly more in-depth answer right now, you might consider putting general pointers in the comment section (once you have enough reputation) – gandalf3 Jul 01 '15 at 05:26