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Old 01-06-11, 05:35 PM   #6
CapnScurvy
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Hi keltos, I've read your thread and Hitman is correct in his assessment in how to get the proper Field of View size with whatever size periscope view opening you use.

As an example, I'm going to use the known American periscope specs as having a True Field of View of 32 degrees with a low power magnification of 1.5x, the high power magnification of 6.0x.

First the game's Camers.dat parameter of "AngularAngle=62.4814" is influenced by the parameter "Viewport=xxxx". Now, I'll be the first to admit I don't understand this relationship, so being able to give you a math lesson on how the 62.4814 (which in Silent 3ditor states is in degrees) relates to a True Field of View of 36 degrees in-game.... I DON'T KNOW!! But it does. And the FoV is 38 degrees when you use the 1280x1024 game resolution!! I don't know why or how I just know it does.

So you may ask, How do you know what the stock game Field of View is? I've tested for it, and I recommend you do the same.

In order to test the true FoV of the periscope (or any periscope image you may wish to use), you must use the only tool that is available to you and that's the periscopes relative compass bearing. You will also need to have a test background to measure. A group of stationary ships set at about equal distance from a stationary sub will do the trick. Try THIS download called "Optical Test Mission Pack". There is an American mission called "Optical Test Mission" that can be activated through JSGME. When it is installed in-game you will find under the American Quick Mission menu a mission entitled "Test 21". Run the mission and you will find yourself in front of a group of ships that can be measured using the compass bearing of the periscope. I also recommend you activate the second mod in the "Pack" called "Big Bearing Compass for Stock Periscope". This will give you a much larger compass to read exactly what degree you are looking at.

NOTE: These two mods were intended for use with the American side of play. So, let me know if your scope mods are only for the German side. If they are, I'll make you a German mission and put the Big Compass Bearing on the German periscope.

Once you have the mods running on a stock game, go to the periscope and choose the low power magnification. Try to put the center line of the scope directly on a degree mark (does not matter what it is) and make sure one of the outer edges of the scope is lined up on a reference point of a ship background (again, it does not matter what reference point you choose, or whether you go left or right) but choose a reference point that you will find easily and precisely when you do the next step. Move the scopes center line onto the point you picked out at the edge of the scope. Now read the compass bearing (and be exact; no almost, or just a bit off will do). The difference between compass degrees of where you started and what the reference point compass bearing reading is will be half the true field of view for the scope. If you count 18 degrees difference between the center line bearing and the edge bearing you measured to, the True Field of View is 36 degrees wide. To see some images of doing this, check out the first couple of posts in this thread.

I could do math all day and couldn't get the "AngularAngle=62.4814" to end up being a true FoV of 36 degrees when the game is running!! BUT, That's what it is!!

So, find out what your specific French periscopes Field of View and Magnification in real life really is. Make a "Periscope_Mask" image to suit the French style (if the French uses the 32 degree FoV, simply measure the Alpha channel black image and divide the width of pixels by 32. This will give you the correct spacing of the Telemeter divisions to put onto the periscope_mask. Every image is different, for instance my periscope images I'm using for Optical Targeting Correction are larger than the stock periscope viewable size. The viewable image size is 768 pixels wide (least wise that's the size on a 1024x1024 canvas). Dividing 32 into 768 you get 24 pixels. So, there is 24 pixels between each Telemeter division on my scopes. This will give you the correct measurement for the FoV of the scope you make, you just need to re size the AngularAngle and Magnification of the Camera.dat file to have the view match the 32 degree width of the scope you made.

You may ask, How did you make the AngularAngle come out to the correct FoV size?

The old saying "If you don't succeed the first time try again" was the way I got it. You know Thomas Edison did hundreds of tries to find the right metal element to put into his light bulb before he found tungsten worked the best. Well, after changing the magnification parameter to what the American scope should be, I just kept fiddling with the AngularAngle until I came up with the correct FoV when I'd restart the game using my "Test 21" mission. No math, I'm just too stupid to know what to do (in this case)!!
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Last edited by CapnScurvy; 01-06-11 at 06:26 PM.
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