Grainy render using Mental Ray and HDRI

[screwcork]

Hi there, I'm totally new to the boards so I may as well introduce myself. The name is Chris and I'm primarily a webdesigner based out of Oslo Norway (Scandnavia, Europe).. Enough with the chit chat, and off to the issue at hand.

I've been using 3DS Max for a couple of weeks now, and got into 3d because it has endless opportunities n terms of art which I'm really in to, Cars, which I'm even more into and last but not least, web design which I do for a living.

I'm currently playing around, trying to get something sensible out of the program! And not unlike many other noobs in 3D I'm pursuiting something realistic and shiny!

Before I start let me just mention, I'm using Mental Ray!

I made a set of rims (or rather I made one and duplicated it) and staged two of them and started the rendering process. I made a basic chrome material based on a tutorial and set up my HDRI environment. When I rendered without any lighting in my scene at a faily good quality using the final gatherer I got this:



It didn't give quite the feel I was looking for and the quality could have been better and lets face it people, it looks akward without any shadows in the scene.

So I added a targetted directional light, with raytraced shadows (I also removed the final gatherer and played a bit with the settings due to grainyness, but it didn't have too much of an effect, so I just rendered it finished to post it here and get some feedback) And this is what I got:



IIIUUUGGHH... Grainyness... :\

Rendering with:

SAMPLES PER PIXEL:

Minimum: 16
Maximum: 64

FILTER:

Type: Lanczos
Width: 4
Height:4

I've also tried using a skylight wth little or no effect in terms of quality.

Any idea of how I should go about fixing the grainyness or maybe you could point me towards a tutorial?

[Jelmer]

Hey chris, welcome to the community! That looks pretty good already, but the noise is an issue of course... The sampling settings are fine i think, i'm not sure about the filter type.
The noise (grain) in the first render isn't very visible but i think it's caused mainly by the HDRI map, what's the resolution of the map you're using?

If you're using max 9 with A&D materials the material settings might also cause problems, for example a low glossiness samples setting will cause noise.

Another cause might be the lighting you're using, with mental ray i always recommend mr Area lights because they're made for mental ray.
Don't forget to set the samples of the area lights higher, because the shadows will be noisy if you set it to 5 - 5, instead try something like 10 - 10 or even 15 - 15.

[screwcork]

Thank you Jelmer. Thats a very good reply, and even though I'm very new to the program it makes alot of sence!

I'll try to alter my settings according to your advice, and hopefully I'll end up with something pretty good looking!

Thanx again

-Chris