[Half Life]

Attached is a Sketchup Dynamic Component which will calculate the necessary Focal Length for "Normal" perspective (ie: what we see with the naked eye) based on your current output pixel size.

It will generate a 35mm equivalent value at the same time (for slightly exaggerated perspective), and it will also let you double check and translate custom Focal Length and Field of View values.

Simply bring into any Sketchup file as a component and use the Component Options dialog (Dynamic Components toolbar) to enter settings and get results.

The Model will illustrate the currently set aspect ratio and the corresponding "Normal" focal length.

http://www.spotoarts.com/jason/AOV%20calculator.skp

Feedback is welcome.

Best,
Jason.

[Richard]

Hey mate! Not quite sure what you are aiming to achieve? Please excuse my dumb or lack of assimilating your idea / workaround! If you are aiming to replicate the human eye is it not just the case of changing SU's FOV to 60?

As said I could be completely missing the point!

I've also been playing around with a camera component to allow a background image to be always with the camera - worked a simple workaround: Just create a SU camera then orbit out (not zoom) select the camera > make component > reload this with the version including background. The background in the conponent is gained by importing an image to SU stretching it to match the FOV guides of a created camera!

Bit hard to explain exactly and I haven't nailed it yet, but is the reload of camera on option for the functionality it offers!

On another note! If you are akin to creating dynamic components could you do anything with the ideas that Stefan and I had regarding a tool for HDRI placement viewing in SU?

[Half Life]

Hey Richard,

This is designed to make the "Field of View" tool (and general perspective distortions) a bit more meaningful and controllable.

The plane at the bottom represents the "filmback/sensor" of the camera. The cone represents the image being projected through the camera "lens" onto the "filmback/sensor" from the idealized "Normal" focal length.

The main point is as you change the size of the desired output aspect ratio the filmback/sensor size changes to match which makes the focal length no longer match the desired perspective distortion.

Ideally there is a balanced placement of the lens from the filmback/sensor which creates "Normal" perspective as we humans generally see it with our naked eyes (Diagonal AOV of 53 degrees)... when you change the filmback/sensor size the proper focal length is no longer the same, therefore consistent perspective is a constantly moving target.

This is not as large of an issue in real cameras as the film/sensor size is not very likely to change in any given camera, but since we can and do change those parameters often in 3D there needs to be some way to predict a desired perspective distortion for any given output.

This DC also creates calculations for 35mm equivalent focal lengths (for slightly exaggerated perspective) -- which could also be desirable, because again the same goal is the point: consistency of output regardless of output aspect ratio.

I created this mostly as a teaching tool for my videos to explain and show how the camera filmback/sensor size can make the FOV tool in Sketchup problematic to utilize well and moreover what settings to look for in Maxwell Studio to control perspective properly.

I got most of my information of wikipedia here: http://en.wikipedia.org/wiki/Angle_of_view


As far as HDRI placement is concerned this will be a moot point when we have the Fire preview engine working as part of the plugin, so I'm just going to leave things as they are on that point.

Best,
Jason.

[Richard]

Your right! Fire - Dam I forget that!! Yep!

Re the DC - mate thanks for the lengthy explanation! I had no idea of the implications! Wow though will play with it and do some testing!

Cheers for both the DC and education!!!!!

[brodie_geers]

Can you post a v7 version? I'm not sure i fully understand what you're saying, and I don't have SU v8.

-Brodie

[Half Life]

Here's one for 7:
http://www.spotoarts.com/jason/AOV%20calculator_v7.skp

Basically the idea is to take something like this and make it more specifically for Sketchup and Maxwell: http://www.radical.org/aov/

Best,
Jason.

[Half Life]

I should note that this DC only gives correct results if you are using the "custom" option in the Cameras tab of the Maxwell Scene Manager.

If you are in viewport mode the height (not the width) is used for filmback long-side size and therefore all the calculations would have to change -- I will most likely update this shortly to add that as an option.

Best,
Jason.