bevyengine/bevy · error

Failed to update PerspectiveProjection: width and height mus

Error message

Failed to update PerspectiveProjection: width and height must be positive, non-zero values

What it means

Raised by PerspectiveProjection::update when the viewport or render-target dimensions passed in are zero or negative, making the computed aspect-dependent projection terms (frustum widths/heights) invalid. The projection matrix cannot be sensibly built from such dimensions.

Source

Thrown at crates/bevy_camera/src/projection.rs:391

        let x = (2.0 * self.near) / (right_prime - left_prime);
        let y = (2.0 * self.near) / (top_prime - bottom_prime);
        let a = (right_prime + left_prime) / (right_prime - left_prime);
        let b = (top_prime + bottom_prime) / (top_prime - bottom_prime);

        let mut matrix = Mat4::from_cols(
            Vec4::new(x, 0.0, 0.0, 0.0),
            Vec4::new(0.0, y, 0.0, 0.0),
            Vec4::new(a, b, 0.0, -1.0),
            Vec4::new(0.0, 0.0, self.near, 0.0),
        );

        self.adjust_perspective_matrix_for_clip_plane(&mut matrix);
        matrix
    }

    fn update(&mut self, width: f32, height: f32) {
        self.aspect_ratio = AspectRatio::try_new(width, height)
            .expect("Failed to update PerspectiveProjection: width and height must be positive, non-zero values")
            .ratio();
    }

    fn far(&self) -> f32 {
        self.far
    }

    fn get_frustum_corners(&self, z_near: f32, z_far: f32) -> [Vec3A; 8] {
        let tan_half_fov = ops::tan(self.fov / 2.);
        let a = z_near.abs() * tan_half_fov;
        let b = z_far.abs() * tan_half_fov;
        let aspect_ratio = self.aspect_ratio;
        // NOTE: These vertices are in the specific order required by [`calculate_cascade`].
        [
            Vec3A::new(a * aspect_ratio, -a, z_near),  // bottom right
            Vec3A::new(a * aspect_ratio, a, z_near),   // top right
            Vec3A::new(-a * aspect_ratio, a, z_near),  // top left
            Vec3A::new(-a * aspect_ratio, -a, z_near), // bottom left

View on GitHub (pinned to 396ca72708)

Solutions

1. Ensure the window/render target has non-zero width and height before the camera renders
2. Delay camera activation until the window is sized
3. Guard code that resizes targets to zero (minimized window)

When it happens

Trigger: Thrown at crates/bevy_camera/src/projection.rs:391 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of bevyengine/bevy@396ca72708 (2026-08-20). Data as JSON: /api/errors/155829e1697c66b7. Report an issue: GitHub.