[fred - elium]

Hi there,

I face 2 linked problems in rhino using maxwell:

1st problem:
I position my camera correctly in order to render in a 800x800 resolution and launch the render.
Then I change the render size from 800x800 to 2000x2000 and the image is framed totally differently: the objects become really smaller in the view.
2nd problem (linked to the previous one):
In order to solve the 1st problem, I switch on the camera heads-up display and the frame does not appear: my window size is smaller than the 2000x2000 resolution.
I tried to find a way to request a 800x800 size rendering in 150 DPI but I don't know if this even exists or not but I can't see how to use the camera heads-up display if this resolution input is not available.

I use the latest Maxwell versions and Rhino 4 SR8

Thanks in advance for your reply,

Cheers, fred

[JDHill]

Before you manually change the output resolution, make sure Lock film ratio is enabled in your camera. Let me know if that helps.

[fred - elium]

Hi JD,

thanks for your quick feedback.
I already tryied it and expect the fact that the ratio between lenght and height is respected (I keep the squarish ratio), it has no impact on the resolution of the image ...

Fred

[JDHill]

What exactly do you mean by 'has no impact'?

The problem is, with Lock film ratio disabled, you are changing the resolution in two stages: first width, then height, or vice versa. When you change only the output width or height, then the film width or height must be compensated, because the output ratio is a function of the film ratio. So, changing them independently (i.e. with Lock film ratio disabled) has this effect:

1a. start: output 800x800, film 24x24
1b. change width: output 2000x800, film 60x24
1c. change height: output 2000x2000, film 60x60

However, with Lock film ratio enabled, this becomes:

2a. start: output 800x800, film 24x24
2b. change width & height: output 2000x2000, film 24x24

It is the 60x24 and 60x60 film sizes produced in step 1b and 1c which are causing your perspective to change. Keep in mind that if you want your output perspective to match the perspective you see in Rhino's viewport, that your film must be either 24mm high or 24mm wide, depending on whether the viewport is wide & short (use 24mm high) or narrow & tall (use 24mm wide).

[fred - elium]

The lock film ratio locks the dimension relation between width and height and this works fine.
But my main problem is that changing tthe size of rendering also changes the centring of the image.
To explain this to you, when I transferrred the scene to Maxwell studio, the same problem occured and I had to change the focal lenght from 80mm to around 192mm to finally find back my initial image centring.

[JDHill]

What were the output and film sizes when you exported to Studio?

[fred - elium]

If I remenber well:
Size was 800x800, film size 24x24
And when modifying the size to 2000x2000, film size was becoming 60x60

[JDHill]

And did you have the ratio locked in Studio before changing the resolution? If you did, then the film should have remained at 24 x 24mm.

Just to be clear, describing the end result of a process is rarely sufficient to infer how that result was obtained. To find most bugs, a specific and repeatable set of steps is required, by which the issue may be reproduced here on my machine.

[fred - elium]

JD,

Sorry for my lack of details regarding my issue ...
The film changed to 60x60mm when I locked the ratio!
It seems that it was not normal...

[JDHill]

Sorry, but I don't seem able to make Studio do that. If I start with a camera where output = 800x800 and film = 24x24, then:

1. make sure the ratio is locked
2. change output width to 2000

I end up with a camera where output = 2000x2000 and film = 24x24, as expected.

[fred - elium]

JD,

I will check it as soon as I can open the scene again (I am actually computing a big image ....) and let you know asap.
Thank you for your feedback,

Cheers, Fred

[fred - elium]

Hi JD,

You are right, I opened again the file that was causing problem and I fully managed to handle the size question as you describe it.
Thank you for your help.

Additionnally, my scene is rendering for 80 hours now (2000x2000 format with multilights on) and everything goes fine on the picture except that the white plastic material (done withe material wizard) is still noisy. I speak of an area made of several parts reflecting with this material
The sampling level is more than 23.
I don't understand why this material (a topcoat and a base) is so long to render.
Is there a special kind of material to avoid to limit the rendering time because I feel that this material has nothing really special.

Thanks in advance for your help,

Cheers, fred

[JDHill]

How white is the white? If you think of colors as energies, a fully-white reflectance means that 100% of the energy which goes in, comes back out again, and that would represent a material which, while not mathematically impossible, never can occur in the real world. In short, with a material like that, you end up with an unrealistic amount of energy bouncing around in the scene -- reduce the efficiency of the material and reduce the life span of light rays.

That said, it may also have much to do with the physical construction of the scene. The more times light must bounce to get to a given area, the lower the probabilities that it does. Lower probability is another way of saying longer time, given a fixed capacity for computation.

[fred - elium]

I think that the white material exactly behave as you describe it, so I will make it with less reflectivity.
Additionnally, the scene is lighted with 3 emitters (2 primary light + 1 auxiliary light) plus an HDR environment that both lights and reflects in the scene.
I also placed in the scene an object to be reflected in a white material ...
And as a an aggravating point, I used the multilight (intensity only, rendering never launched with HD size rendering when I tried to launch multilight with both intensity and color).
I will proceed to the update according to what you said in order to optimise my scene.

I was questionning myself on one issue: I have very few transparent material used in my scene but I activated all the render layers except the indirect refraction.
Do these layers activated have an impact on every single object of the scene (even the plain color object with no transparency) or the caustic layers refer specifically to the transparent objects?

Cheers, Fred

[JDHill]

I haven't used those features very much at all, so I couldn't really say much about them. Since this is not really plugin-related, it would probably be best if you posted about it in the main Maxwell forum.