v.readDebug()

Use v.readDebug(node) after running a debug-enabled node.

const node = v.pass(kernel, bindings, { debug: true });

v.run(node);

const result = await v.readDebug(node);

Print Logs

For quick inspection, call print().

result.print();

Console output:

[1,0,0] vector: 0, 1, 2, 3

The prefix is the invocation id that produced the log: [gid.x,gid.y,gid.z].

Read Logs Yourself

logs is an array of decoded records.

for (const log of result.logs) {
    console.log(log.gid, log.kind, log.message, log.value);
}

Each log has:

Field	Meaning
gid	Invocation id as [x, y, z]
kind	Logged value kind, such as f32 or vec4f
message	Optional message from the shader
value	Number or number array

Buffer Size

Debug records are stored in a hidden debug buffer. The default payload size is 16 KiB.

Increase it when you expect more logs.

const node = v.pass(kernel, bindings, {
    debug: { bufferSize: 64 * 1024 }
});

bufferSize is measured in bytes.

Dropped Logs

If the debug buffer fills up, Volten keeps the records that fit and reports how many were dropped.

if (result.dropped > 0 || result.truncated) {
    console.warn('Some debug logs were dropped.');
}

Field	Meaning
dropped	Records the shader tried to write after the buffer was full
usedWords	Number of 32-bit words used by written records
truncated	The recorded cursor moved past the available payload
bufferSize	Debug payload size in bytes

Debug output vs data output

v.readDebug() reads only debug logs. Use v.read() to read buffers, node outputs, or handles.