Rendering is Labor Intensive

[Cad64]

I'm still new to most of this. Is MENTAL RAY another software package? And I do not have any access to 3DSMAX so working in that environment is not possible for now.

 

Mental Ray is the default renderer that Autocad has been using since 2007. When you render in Autocad, you are rendering with Mental Ray.

 

I'm glad to hear that you got the render time down under 5 minutes. It sounds like the "Sun and Sky Background" is what's driving up the render time. Post back and let us know how the background image works out.

 

FYI, if the background looks too dark after rendering, play with the "Self Illumination" slider, in the background image material slot, to brighten it up.

[Cad64]

I use mental ray to as my renderer and to speed this up you need more processor power, as far as I can see the amount of RAM you have really only decides whether or not the scene will render or not (i.e. crash) but the purchase was definately a neccesity.

 

I don't know about scan line renderers but with mental ray, the number of cores also affects the speed, at work I have 8x 2.66GHz cores which is a shed load better than the 2x 2.4GHz cores I have at home.

 

The number of processors is definitely the key to getting the fastest possible render times. The more processors you have, the faster the job can be finished. It's just like working on a set of construction plans. If you have 4 people working on the set, the project will be finished in much less time than if only 1 person is doing the whole thing.

 

We have been in the process of building a render farm at work, over the past few months and right now we have 6 computers hooked up to the farm. Two of them have duo core processors, the other four are single cores. So we have a total of 8 cores available for rendering. Unfortunately the single core machines are relic's and really don't help much, but the two duo cores working together really helps speed up the rendering process.

 

I have run countless tests, and have found that two duo core machines hooked together, with 2GB RAM each, can render much faster than one duo core machine with 3GB RAM.

 

RAM is important though, when trying to get the fastest possible render times. You can have an 8 core machine, but if you don't have enough RAM to store all the render data as it's being calculated, then some of that information will start overflowing and getting paged to your hard disk, slowing down the render. Reading data from the HDD is much slower than reading that same data from your RAM.

 

RAM may not have been an issue for you Bill, because your scene is very small with only a few materials, etc. But once you start building larger, more complex scenes, RAM will start to become a factor in your renderings.

[Bill Tillman]

Okay, I think I have some interesting data from my rendering test. First, I have a laptop with a Dual Core AMD 64 cpu but still with only 896 MB RAM. But then I ran the render on it using an image as the background, not Sky+Illumination it completed in only 63 seconds. Now the catch here is that the problem I had before with the pattern in the shingles running in the same direction on all planes was apparent again with this machine. I recall that I ran the render at my office where I have a slower machine but it has 2GB RAM so I think we can say that its a video card issue with this. The video card's capabilities seems to have something to do with whether the texture I used oriented in the plane of the material I applied it to. My machine with the new memory I added yesterday has a Navidia G6100 or something like that.

 

While this rendering leaves alot to be desired it at least gets me in the area I'm heading and it only took 4-1/2 minutes on the desktop unit I normally work with. Turning off Sky+Illumination increased the speed dramatically and to be honest, the Sky background with AutoCAD kind of looks like a cloudy day and is boring. This background is great but I can see that getting the persepctive of the object just right is important in acheiving the desired effect.

[papagyi]

Did you turn on "GI" from advance rendering setting?

[Organic]

That looks awesome Bill.