IRaconI

I'm trying to create functionality to take in a 2d screen coordinate and return the block type at that point, as well as the distance to that block. I've tried this function, but it returns a ray in seemingly a random direction. ScreenWidth and ScreenHeight are the Minecraft window size. (I didn't use the built in inverse function because it was giving the wrong result for some reason. I manually verified.) public static Vec3 GetRay(float screenX, float screenY, Camera cam) { Matrix4f projectionMatrix = getProjectionMatrix(); Matrix4f viewMatrix = getViewMatrix(cam); float ndcX = (2.0f * screenX) / ScreenWidth - 1.0f; float ndcY = 1.0f - (2.0f * screenY) / ScreenHeight; Vector4f screenVector = new Vector4f(ndcX, ndcY, -1.0f, 1.0f); Matrix4f inversePM = new Matrix4f(projectionMatrix); float detPM = inversePM.adjugateAndDet(); inversePM.multiply(1.0f / detPM); screenVector.transform(inversePM); screenVector.setZ(-1.0f); screenVector.setW(0.0f); Matrix4f inverseVM = new Matrix4f(viewMatrix); float detVM = inverseVM.adjugateAndDet(); inverseVM.multiply(1.0f / detVM); screenVector.transform(inverseVM); Vec3 direction = new Vec3(screenVector.x(), screenVector.y(), screenVector.z()); direction = direction.normalize(); return direction; } private static Matrix4f getViewMatrix(Camera cam) { Vec3 cameraPos = cam.getPosition(); Vector3f camPos = new Vector3f((float) cameraPos.x, (float) cameraPos.y, (float) cameraPos.z); Vector3f forward = cam.getLookVector(); forward.normalize(); Vector3f up = cam.getUpVector(); up.normalize(); Vector3f right = cam.getLeftVector(); right.mul(-1.0f); right.normalize(); float[] values = { right.x(), up.x(), -forward.x(), 0, right.y(), up.y(), -forward.y(), 0, right.z(), up.z(), -forward.z(), 0, -camPos.dot(right), -camPos.dot(up), -camPos.dot(forward), 1.0f }; Matrix4f viewMatrix = new Matrix4f(values); return viewMatrix; } private static Matrix4f getProjectionMatrix() { double fov = Math.toRadians(90.0); double aspectRatio = ScreenWidth / ScreenHeight; double nearPlane = 0.05f; double farPlane = 1000.0f; double yScale = 1.0f / Math.tan(fov / 2.0f); double xScale = yScale / aspectRatio; double frustumLength = farPlane - nearPlane; float[] values = new float[]{ (float) xScale, 0.0f, 0.0f, 0.0f, 0.0f, (float) yScale, 0.0f, 0.0f, 0.0f, 0.0f, (float) -((farPlane + nearPlane) / frustumLength), -1.0f, 0.0f, 0.0f, (float) -((2.0f * nearPlane * farPlane) / frustumLength), 0.0f }; return new Matrix4f(values); }