# Camera Projection Matrizes..?

Discussion in 'Programming' started by SirDude, Oct 10, 2019.

1. ### SirDudeMember

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Mar 16, 2019
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Hi, so I'm using the new Camera Projection Matrix added in GMS 2, but I don't really understand how to get the data once it's set up. For example, how do I get the x and y position of the camera like
camera_get_view_x(view_camera[0]) used to do? I tried to calculate it myself with:
var cw = camera_get_view_width(view_camera[0]);
var ch = camera_get_view_height(view_camera[0]);
var cleft = x - (cw / 2);
var ctop = y - (ch / 2);

,but there has to be an easier way, right? (also I'm actually not even sure if that is correct...)

2. ### YalGMC MemerGMC Elder

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Isn't there functions named camera_get_view_x and camera_get_view_y to get their top left corner? Then you can just add the width/height to get the bottom right corner. The camera's center is the average of those points.

3. ### SirDudeMember

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Mar 16, 2019
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Unfortunately, camera_get_view_x and camera_get_view_y are (for whatever reason) always 0 using Projection Matrizes ...

4. ### flyingsaucerinvasionMember

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Jun 20, 2016
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You should already know the position of your camera if you've built it using matrices. However, it can be extracted out of the view matrix if needed.

Are you using a perspective projection with a top-down view? And do you need to know the position of the camera, or the position of the 2d view, which is located at view_center - view_size/2 (or the equivalent considering a perspective projection is in use)? If the game is not top-down, then there won't be any equivalent.

Last edited: Oct 10, 2019
5. ### SirDudeMember

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Mar 16, 2019
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I was using the Smooth Camera shown by Shaun Spalding on Youtube, but I am very new to this method so I didn't understand all of it. I want to know the position of the 2d view and can't figure out an easy way to get it...
This is basically what I was trying to do with the code in the first post, but I don't think it works correctly

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7. ### flyingsaucerinvasionMember

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If you show us exactly how you are setting up your camera or your view and projection, we can be sure we are helping you get correct answers to your question.