I want to merge two models into one, but keep reporting the error "attempt to clone with unknown class"

[wwr1982]

My code is as follows:

Logger.initializeToConsole();
Logger.setLevelDefault(LogLevel.Trace);
Logger.setLevel("imodel-transformer", LogLevel.Trace);
let sourceDb: IModelDb;
let sourceDb2: IModelDb;
let targetDb: IModelDb;
const sourceFile ="C:\Users\wwr\Downloads\aa\aa.bim";
const sourceFile2 ="C:\Users\wwr\Downloads\bb\bb.bim";
const targetFile ="C:\Users\wwr\Downloads\c\c.bim";
sourceDb = SnapshotDb.openFile(sourceFile);
sourceDb2 = SnapshotDb.openFile(sourceFile2);
if (IModelJsFs.existsSync(targetFile)) {
  IModelJsFs.removeSync(targetFile);
}
targetDb = StandaloneDb.createEmpty(targetFile, { // use StandaloneDb instead of SnapshotDb to enable processChanges testing
  rootSubject: { name: ${sourceDb.rootSubject.name}-Transformed },
  ecefLocation: sourceDb.ecefLocation,
});
const transformerOptions: TransformerOptions = {
  simplifyElementGeometry:true,
  noProvenance:true,
};
try{
  await Transformer.transformAll(sourceDb, targetDb, transformerOptions);
  await Transformer.transformAll(sourceDb2, targetDb, transformerOptions);
  sourceDb.close();
  targetDb.close();
  return "test";
}
catch(error:any)
{
  console.log(${error.message}\n${error.stack});
}
return "OK";

My files to be merged are：
bimfile.zip

Thank you！

[ben-polinsky]

@MichaelBelousov

[MichaelBelousov]

@wwr1982 Transformer.transformAll is from the test-app, which is a testing tool. I recommend using the transformer library directly unless you are trying to hack the test-app for a basic CLI.

So you should be using IModelTransformer.processAll (the library equivalent of transformAll) and IModelTransformer.processSchemas.

But technically transformAll does this, so I will investigate

[MichaelBelousov]

also next time please include a complete reproduction so it's less work on the maintainers to piece together your code into something that we can (safely) run and will accurately depict your issue.

My version

const { Logger, LogLevel } = require("@itwin/core-bentley");
const { SnapshotDb, IModelHost, StandaloneDb, IModelJsFs } = require("@itwin/core-backend");
const { Transformer } = require("@itwin/imodel-transformer");
const path = require("node:path");
async function main() {

IModelHost.startup();
Logger.initializeToConsole();

Logger.setLevelDefault(LogLevel.Trace);

Logger.setLevel("imodel-transformer", LogLevel.Trace);
/** @type{IModelDb} /

let sourceDb;

/* @type{IModelDb} /

let sourceDb2;

/* @type{IModelDb} */

let targetDb;
const sourceFile = path.join(__dirname, "./aa.bim")

const sourceFile2 =  path.join(__dirname, "./bb.bim")

const targetFile = path.join(__dirname, "./c.bim")
sourceDb = SnapshotDb.openFile(sourceFile);

sourceDb2 = SnapshotDb.openFile(sourceFile2);
if (IModelJsFs.existsSync(targetFile)) {

IModelJsFs.removeSync(targetFile);

}
// use StandaloneDb instead of SnapshotDb to enable processChanges testing

targetDb = StandaloneDb.createEmpty(targetFile, {

rootSubject: { name: ${sourceDb.rootSubject.name}-Transformed },

ecefLocation: sourceDb.ecefLocation,

});
/** @type{TransformerOptions} */

const transformerOptions = {

simplifyElementGeometry: true,

noProvenance: true,

};
try {

await Transformer.transformAll(sourceDb, targetDb, transformerOptions);

await Transformer.transformAll(sourceDb2, targetDb, transformerOptions);

sourceDb.close();

targetDb.close();

return "test";

} catch(error) {

console.log(${error.message}\n${error.stack});

}
return "OK";

}
void main()

[MichaelBelousov]

this occurs because your input files have the same version of a dynamic schema (RevitDynamic), but bb.bim contains classes in that dynamic schema which aa.bim does not. I will investigate this further.

[wwr1982]

Thank you.

[MichaelBelousov]

In order to merge iModels with dynamic schemas using the transformer, you must manually merge the dynamic schemas, import the new merged one (it can be an update of one of the two), and remap all elements from the other schema into it.

We are working on additional automation of this process.