Eliminating Graininess in Video

I finished and posted a video here: http://youtu.be/6IbNTX9UDwM There is too much graininess in the background. Today, I attempted to fix the problem by getting rid of an hdr background image, deleting a sun lamp and replacing it with an emission plane. It’s better. But still, the only way I can get rid of the graininess to my liking is by also rendering at 400 or even 500 samples. On my computer one frame took four and a half minutes to render. The video has 3000 frames. Can someone tell me why I am having graininess problems? Also, is there a way to fix this problem without having to render each frame at 400 samples? I am a beginner, so hopefully there’s an easy fix.

Render after my attempts to fix the graininess problem:


Blender file:

There’s a very easy fix. Use The Blender Internal render engine which would be ideal for your subject matter in my opinion and animating it. Nice clip albeit maybe a minute to long. The grain is referred to as noise by the way. Try a spotlight if for some reason you have to use a raytracer. Also use Limited Global Illumination in the dropdown menu and set the Bounces to: Max: 4. That should help and get you started. But, to see render times around 1 minute means going to Blender Internal.

4 and a half minutes is almost nothing in terms of render time for an animation. Switching to BI likely won’t save you much time, and may even take longer with blurred glossy reflections like those on the character. Switch back to using the HDR map in the environment, make sure that Importance Sampling is turned on for the environment, and try using the Branched Path Tracing integrator instead of the standard path tracing. Keep your bounces low, too. In an outdoor scene there’s no reason to have more than a couple of diffuse bounces. Turn off caustics and turn on glossy blurring in the render panel as well. The scene looks to have a lot of GDG and DGD bounces, which are likely to result in excess grain and fireflies.

Switching to Blender Internal isn’t an easy solution. BI materials are totally alien when all you know is Cycles.

First, one tip: When you render an animation, type #frame as value for the Seed. It randomizes the noise. (That makes things already less ugly.) :wink:

Next, your light is really too strong. Strong, small and pure white lights are great sources of noise. Reduce the strength to no more than 50 (And that’s already a lot in my books!) and increase to Exposure to compensate eventually. Or else you can try a sun… or to use RGB curves in the Compositor. And don’t forget the Clamp setting. It’s not only for the fireflies, it also prevents Cycles from pumping too much light into your scene and from creating more noise.

As for the speed, there are a lot of things to take in consideration but I’d concentrate on the “weight” of the mesh first. You’re not filming ants crawling inside a haystack so… 32 vertices for the cylinders, that’s way too much. 8 are enough. 12 are already quite a waste for such a distant view. Remove also all the hidden faces and useless edge loops. You’re animating a mechanical character so forget about the perfectly square quads. Use only edge loops to tighten your mesh at the edges and to make the Subsurf modifier behave. Subsurf modifier which must be used reasonably. No need to crank up the level up to 5 if you can’t tell the difference with the level 2. (Especially for something in motion.) And if you use the Subsurf to hide some imperfections in your mesh, fix your mesh instead. A few edge loops are much lighter than a level of Subsurf. (I do that sometimes…) :wink:

Last but not least, simply your materials. A heavy node tree can slow down Cycles… drastically! Subtleties and tiny details are lost in an animation. Don’t bother.

Also, since your scene is rather empty, use “Spatial Split” at least. It really works. To switch to “Limited Global Illumination” and to reduce the bounces can help too. Even “Direct Light” can be enough if you compensate the absence of the global illumination with a slightly colored sun. (It will work well with your open scene, IMHO.)

That’s all I can think of for the moment.