fn draw(
        &mut self, 
        render_pass: Arc<dyn RenderPassAbstract + Send + Sync>, 
        dynamic_state: &mut DynamicState,
        device: Arc<Device>,
        queue: Arc<Queue>,
        pipeline: Arc<dyn GraphicsPipelineAbstract + Send + Sync + 'static>,
        vertex_buffer: Vec<Arc<CpuAccessibleBuffer<[Vertex]>>>,
    ) { 
draw code... its same as whats in the draw function in event.run
}

expected trait object `dyn vulkano::buffer::traits::BufferAccess`, found struct `vulkano::buffer::cpu_access::CpuAccessibleBuffer`

@pac85_gitlab The error message is also showing something strange. It's saying there is something with descriptor 1 of set 0. I suppose it should complain about descriptor No 3, but anyway there is something with descriptors and layouts. The set's layout itself described here: https://gitlab.com/pac85/GameKernel/-/blob/master/data/engine/shaders/third_pbr/frag.glsl#L10 First thing that seem to be mistaken here is numeration of bindings. The bindings should start with Zero, not with One. The might be a cause of a strange numeration in the error.

Most likely what really happened is that first time you run the frame you read an image from iterator here: https://gitlab.com/pac85/GameKernel/-/blob/master/src/game_kernel/subsystems/video/renderer/mod.rs#L1429 So, the entire number of entries was 3(as required by the shader's layout) and Vulkan/Vulkano somehow resolved it. The second time you run this code the iterator(or a source of the iterator) was already exceeded/emptied so the descriptor set was described with 2 entries only, which contradicts shader's layout.

The resolution is you need to somehow pass a sampler attachment in both cases of that condition. Even if you don't have an image you need to put a dummy image(like 1x1 pixel) to fill the gap in the layout, or use different shader with the different layout. Also, if you want to change "albedo" texture sampler often and don't want to touch "diffuse" and "specular" as often as "albedo", you can split descriptor set into two independent sets, and describe them independently too caching the first set(with diffuse and specular). It would be more efficient than recreating descriptor sets every frame which is expensive operation per se.

println!("cargo:rerun-if-changed=src/shaders/shader.fs");