[Ernesto]

The offset camera of maya don´t work in MX.

[lllab]

we have the same problem in the cinema plugin.

until this is fixed i personally dont use maxwell for my work...

i hope very much for 1.2 to add this important feature.
it is on the wishlist since long for high priority.

hope nl doesnt forget this.
thanks

cheers
stefan

[mverta]

I'm not sure what you're after there, but why don't you try a longer lens and/or just increasing the Height dimension in Image Size (Render Globals>Common Tab).

_Mike

[Fernando Tella]

Does Maya have region render? It would have the same effect.

[SunlightRocker]

I dont understand? The only diference in the two renders is camera-tilt? no?

[dyarza]

Yes, Camera Tilt-Shift or film offset, whatever you want to call it.

We have been hoping for this to be implemented from day one. It is true that you can achieve the same by rendering a much taller resolution and if you had a render region you could do it too. But both Maya and C4D have this feature and it would be nice for MR to take the value so we can compose our images in the application viewport the way we already do.

[mverta]

Changing the output resolution does show up in the viewport. You can easily preview it using Show Resolution Gate. You already have this functionality. Compose your scene the way you normally do and hit render.

_Mike

[Ernesto]

Mverta,

The Offset settings, were created to perform accurate perspective corrections without ending up with incrediblely high resolutions that Maxwell cannot handle.
So as you may understand in my case increasing resolution is not possible.
Even if a window rendering could be posible, how can I pick the same window twice?
It cannot be that hard to make it work! it is a simple matter!

Ernesto

[mverta]

#1) The film offset was NOT created to do any kind of perspective correction or shift-lens effect whatsoever. It is simply another way of offsetting the image relative to the image size, which is why my suggestion is valid in the first place: what I'm suggesting you do is exactly what you were doing anyway, from a different box. Feel free to consult the Maya manual if you'd like.

Further, I don't know what you're talking about with "window render" but this sort of thing should absolutely not put you into a memory issue. Resolution is resolution. If you are able to render the pixels using an offset filmback, you can render the pixels using image dimension, which in this case precisely duplicates the filmback offset effect. Maxwell does not natively support filmback offset, and fortunately for you, is entirely unnecessary, since you have this option. The functionality you require is present and working - you just have to type your numbers into a different box. Again, if you can render the full building using offset, you can render the full building using image settings. I've done a bunch of tests on this since your initial post, and it works.

_Mike

[dyarza]

The functionality you require is present and working - you just have to type your numbers into a different box. Again, if you can render the full building using offset, you can render the full building using image settings. I've done a bunch of tests on this since your initial post, and it works.

_Mike

Exactly! Which is why it should not be a big deal to get MR to read those values and render the region accordingly.

This is a perfectly reasonable request and one that we have been expressing in the wishlist for quite some time, I am not sure why you have such opposition to it. Correcting the perspective is as common in Architectural Photography as setting the exposure and these host applications support it in a very simple way. It would be very nice for MR to do so too.

[mverta]

Film offset is NOT shift lens/perspective correction in any way. In real photography, shift lenses are mounted in a housing which allows the lens to be moved laterally. Additionally, some housings also have a tilt capacity so you can hold receding planes in focus without having to stop down. The filmback in these cameras does not move, or have an offset of any kind. The Maya camera does not have such shift-lens capability.

What Ernesto was asking for was NOT shift lens capability, which Maya doesn't support, but a film offset feature which he feels approximates the look of a shift lens. I told him he already has this capability via the image output control, which he does. Technically, Maya correlates the two such that they provide the same functionality.

In neither case, Maya/Mental Ray or Maxwell is a shift lens technique being employed. It just sort of looks like it... and it still does using the offset not in the filmback but in the resolution settings. I am not opposed to the idea of a shift lens feature, but that's not what's being discussed here. He asked for a functionality he already has, and I showed it to him. Any confusion has arisen from a lack of understanding about what was actually going on in the camera attributes and/or a lack of understanding of what a shift lens does.

But again, the bottom line is that the functionality Ernesto was looking for is already present.

_Mike

[Ernesto]

It is not clear to me.

Requests:
It is not possible to change the position of the camera.
It is not possible to change the camera's lens.
Obviously the image must have only two vanishing points.

Is this the solution that you propose ?

[mverta]

No, it's not.. Show me your un-offset framing without res increase... Also, can you screenshot me your camera attribute editor with the filmback tabs rolled out? Also, which Maya are you using?

_Mike

[Mihnea Balta]

The Maxwell camera model does not include any kind of shift-lens (or film offset) functionality. We could fake it by enlarging the resolution "behind the scenes" and doing a region render. However, there are important drawbacks:
- Maxwell still allocates memory for the full-resolution image, even though it only renders a part of it
- the image saved by mxcl (and displayed during the render) will have a black region

The second problem can be alleviated by cropping the image when it's brought into the render view, but it would still require you to save the image manually from the RV. The first problem can become pretty bad if you use a large offset. For example, when using 36mm film and a resolution of 640x480, a vertical offset of 0.7 expands the vertical resolution to 1112 pixels (2.3 times larger). If you are rendering at print resolution you can quickly run out of memory.

I've just done a quick&dirty implementation using this trick and the black bands are not nice to look at. :)

If you want to compute the required resolution and see if it's acceptable for your scenes, here's the formula for vertical offset (the terms are arranged so that it's as intuitive as possible):

Code: Select all

resolutionAspect = horizontalResolution / verticalResolution
filmAspect = filmWidth / filmHeight
extraHorizontalResolution = verticalResolution * (2 * abs(verticalOffset) / filmHeight) * (resolutionAspect / filmAspect)

The "abs" operator takes the absolute value of the number (kills the sign). Film size (width and height) is called camera aperture in the Maya UI. This formula assumes that you have set "Fit resolution gate" to "Horizontal", otherwise there are some extra complications.

[lllab]

Hi Mverta,

shift lenses move the film behind the lense.
this IS the same as offsetting the image in 3d software.

3d Architects and Visualisation uses this all the time. it produces the exact SAME effect like a shift lense(not like a tilt lense though).

it is used to offset the horizont of an image up or down. so architects can have images where the vertical lines stay parallel, and still have a correct real world perpective( the system 3dmax uses does not produce correct parepective p.e.).

in maya and cinema 4d there is also the possibility to offset to the side.
great effects for architects can be done with this.

a friend of mine is architectural photographer and does the same with his linhof camera / see also link: http://www.linhof.de/german/index.html

most good arch photographers use camera shift(offset) very often in their images. so it would be just normal to have this ina highend "photography" system like maxwellrender that also wants to simulate real world photography.

cheers
Stefan