Problem with orthographic camera

[Temechon]

Hi !

I wanted to create an orthographic camera (for a 2d view of a 3d scene) with a Camera, but I detected a little issue in Camera.getProjectionMatrix line 61 : I think this._projectionMatrix is missing as last parameter.

Moreover, I cannot have a correct orthographic camera on Y axis looking on (0,0,0). On Z axis, it works great, but the display is weird on axis X or Y. I thought the problem was in the function Matrix.OrthoOffCenterLHToRef, but I can't find it...
Can you help me ?

[deltakosh]

You're ABSOLUTELY right :) I'll fixed it right now^^
The code for Matrix.OrthoOffCenterLHToRef is in babylon.math.js. Here is the code:

BABYLON.Matrix.OrthoOffCenterLHToRef = function (left, right, bottom, top, znear, zfar, result) {
    result.m[0] = 2.0 / (right - left);
    result.m[1] = result.m[2] = result.m[3] = 0;
    result.m[5] = 2.0 / (top - bottom);
    result.m[4] = result.m[6] = result.m[7] = 0;
    result.m[10] = -1.0 / (znear - zfar);
    result.m[8] = result.m[9] = result.m[11] = 0;
    result.m[12] = (left + right) / (left - right);
    result.m[13] = (top + bottom) / (bottom - top);
    result.m[14] = znear / (znear - zfar);
    result.m[15] = 1.0;
};

[Temechon]

Thank you David :)
Maybe I was not clear in my second sentence, I found the code of this function, but couldn't find the issue in it.

Anyway, do you know why I can't have an orthographic camera on X or Y axis looking at my scene ?

[deltakosh]

Strange...could you share you code so I can try to find the issue?

[Temechon]

Nothing fancy here. Here is my code :

var canvas = document.getElementById("renderCanvas");
var engine = new BABYLON.Engine(canvas, true);
var scene = new BABYLON.Scene(engine);

// Camera on Y axis looking at (0,0,0)
var camera = new BABYLON.FreeCamera("Cam", new BABYLON.Vector3(0,-10,0), scene);
camera.setTarget(new BABYLON.Vector3.Zero());

var box = BABYLON.Mesh.CreateBox("box", 1, scene);
box.position = new BABYLON.Vector3(1, 0, 0);

var renderFunction = function () {
          scene.render();
};
engine.runRenderLoop(renderFunction);
camera.attachControl(canvas);

When I execute this code, nothing is displayed. I have to attach a control to the camera and rotate the view to see my scene.

[deltakosh]

Ohh I know this bug :) This is related to maths^^
just move the box a little bit just to ensure the box is not perpendicular to its target:

camera.setTarget(new BABYLON.Vector3(0, 0, 0.001));

[Temechon]

Perfect, it's working great :)

Thank you !!