gfx-rs/wgpu · error

Feature `EXPERIMENTAL_RAY_TRACING_PIPELINES` not enabled

Error message

Feature `EXPERIMENTAL_RAY_TRACING_PIPELINES` not enabled

What it means

Panic in the Vulkan encoder's trace_rays: device.extension_fns.ray_tracing was None, i.e. the VK ray tracing extension functions were not loaded because the corresponding experimental ray tracing feature was not enabled on the device at creation.

Solutions

  1. Create the device with the experimental ray tracing features enabled
  2. Only call trace_rays after verifying the device supports ray tracing
Defensive patterns

Strategy: validation

When it happens

Trigger: Thrown at wgpu-hal/src/vulkan/command.rs:1436 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of gfx-rs/wgpu@3e11ff59bf (2026-09-03). Data as JSON: /api/errors/c34226cd38c20fec. Report an issue: GitHub.

Appendix: source

Thrown at wgpu-hal/src/vulkan/command.rs:1436

        &mut self,
        count: [u32; 3],
        ray_generation_group_data: crate::PipelineGroupData<super::Buffer>,
        miss_group_data: crate::PipelineGroupData<super::Buffer>,
        intersection_group_data: crate::PipelineGroupData<super::Buffer>,
    ) {
        let ray_tracing_functions = self
            .device
            .extension_fns
            .ray_tracing
            .as_ref()
            .expect("Feature `EXPERIMENTAL_RAY_TRACING` not enabled");

        let ray_tracing_pipeline_functions = self
            .device
            .extension_fns
            .ray_tracing_pipelines
            .as_ref()
            .expect("Feature `EXPERIMENTAL_RAY_TRACING_PIPELINES` not enabled");

        let get_device_address = |buffer: &super::Buffer| unsafe {
            ray_tracing_functions
                .buffer_device_address
                .get_buffer_device_address(
                    &vk::BufferDeviceAddressInfo::default().buffer(buffer.raw),
                )
        };

        unsafe {
            ray_tracing_pipeline_functions.cmd_trace_rays(
                self.raw_handle(),
                &vk::StridedDeviceAddressRegionKHR {
                    device_address: get_device_address(ray_generation_group_data.buffer)
                        + ray_generation_group_data.offset,
                    stride: ray_generation_group_data.stride,
                    size: ray_generation_group_data.stride /* no need for multiplying by count, vulkan requires the ray gen sbt to be just one group */,
                },

View on GitHub (pinned to 3e11ff59bf)