Model rendering from +z to -z and rotating around a point doesnt showing.

[Joshi Elijah]

Hi,

        I am trying to rendering a model but it is projecting behind the camera, i am thinking of the problem being in the projection matrix from the link having the same problem https://stackoverflow.com/questions/23187262/lwjgl-projection-matrix-nothing-happens. I modified the projection matrix but still nothing happens, this is my projection matrix

private static final float FOV = 70;
	private static final float NEAR_PLANE = 0.1f;
	private static final float FAR_PLANE = 10000;

private void createProjectionMatrix() {
		float aspectRatio = (float) Display.getWidth() / (float) Display.getHeight();
		float y_scale = (float) ((1f / Math.tan(Math.toRadians(FOV / 2f))) * aspectRatio);
		float x_scale = y_scale / aspectRatio;
		float frustum_length = FAR_PLANE - NEAR_PLANE;

		float bottom = -NEAR_PLANE * (float) Math.tan(Math.toRadians(FOV) / 2f);
		float top = -bottom;
		float left = aspectRatio * bottom;
		float right = -left;

		projectionMatrix = new Matrix4f();
		projectionMatrix.m00 = x_scale;
		projectionMatrix.m11 = y_scale;
		projectionMatrix.m20 = (right+left) / (right-left); //
		projectionMatrix.m21 = (top+bottom) / (top-bottom); //
		projectionMatrix.m22 = -((FAR_PLANE + NEAR_PLANE) / frustum_length);
		projectionMatrix.m23 = -1;
		projectionMatrix.m32 = -((2 * NEAR_PLANE * FAR_PLANE) / frustum_length);
		projectionMatrix.m33 = 0;
	}

Can someone help me ?    this is important for me.

[KaiHH]

The values for the projection matrix are 100% correct. Did you also take into account that such a projection matrix inverts the Z axis, transforming a vector from a right-handed coordinate system to OpenGL's expected left-handed clip space coordinate system? So, without any additional transformation, with your matrix everything will be visible with a Z value between -0.1 and -10000.0 (with sensible values for x and y of course).
If you multiply the vector (0, 0, -1, 1) by that matrix (with aspect ratio of 1) and divide by w, the result should be (0, 0, 0.8, 1), so: visible.

[Joshi Elijah]

First of all thanks for your interest kaiHH, These are my vertices

float[] vertices = {
				1409.598f, -58.85f, -1471.946f,
				1460.572f, -58.9047f, -1462.047f,
				1408.506f, -20.5531f, -1471.137f
		};
		
		int[] indices = {
			0, 1, 2
		};

this is my transformation matrix and viewMatrix

public static Matrix4f createTransformationMatrix(Vector3f translation, float rx, float ry,
			float rz, float scale) {
		Matrix4f matrix = new Matrix4f();
		matrix.setIdentity();
		Matrix4f.translate(translation, matrix, matrix);
		Matrix4f.rotate((float) Math.toRadians(rx), new Vector3f(1,0,0), matrix, matrix);
		Matrix4f.rotate((float) Math.toRadians(ry), new Vector3f(0,1,0), matrix, matrix);
		Matrix4f.rotate((float) Math.toRadians(rz), new Vector3f(0,0,1), matrix, matrix);
		Matrix4f.scale(new Vector3f(scale,scale,scale), matrix, matrix);
		return matrix;
	}
	
	public static Matrix4f createViewMatrix(Camera camera) {
		Matrix4f viewMatrix = new Matrix4f();
		viewMatrix.setIdentity();
		Matrix4f.rotate((float) Math.toRadians(camera.getPitch()), new Vector3f(1, 0, 0), viewMatrix,
				viewMatrix);
		Matrix4f.rotate((float) Math.toRadians(camera.getYaw()), new Vector3f(0, 1, 0), viewMatrix, viewMatrix);
		Vector3f cameraPos = camera.getPosition();
		Vector3f negativeCameraPos = new Vector3f(-cameraPos.x,-cameraPos.y,-cameraPos.z);
		Matrix4f.translate(negativeCameraPos, viewMatrix, viewMatrix);
		return viewMatrix;
	}

you can find my complete project from this link https://www.dropbox.com/sh/ps9uu2clslke3qd/AADzqmNvCjslMipVvCMusuLCa?dl=0

Are my vertices too long for showing inside the camera ? Am working on this from a week now, Really happy if this gets sorted out.