Function render_cylinder_compute_offscreen 

pub fn render_cylinder_compute_offscreen(
    desc: &CylinderDescriptor,
    tess: TessFactor,
    face_id: u32,
    cam: &Camera,
    opts: &RenderOpts,
) -> Result<RenderOutput, RenderError>

Render a compute-meshed cylinder offscreen to a shaded color image + face-id buffer.

The cylinder is meshed entirely on the GPU from desc at the tess LOD: a compute pass evaluates the parametric surface into vertex + index storage buffers, which are then drawn by the same offscreen mesh pass as the solid path. Every emitted vertex carries face_id (use 1 if you have no real face).

Errors

• RenderError::InvalidSize if opts.width or opts.height is zero.
• RenderError::NoAdapter / RenderError::DeviceRequest on GPU setup.
• RenderError::BufferMap / RenderError::Poll on readback failure.