要使用Autodesk Forge设计自动化/模型衍生API来查看缓存的svf文件，可以按照以下步骤操作：

1. 获取访问令牌：首先，需要获取一个有效的访问令牌，以便调用Forge API。可以使用OAuth 2.0流程或其他身份验证方式来获取令牌。

2. 创建模型衍生作业：使用Design Automation API创建一个模型衍生作业，以便将源文件转换为svf格式。可以使用以下代码示例来创建作业：

import requests
import json

def create_derivative_job(accessToken, bucketKey, objectName, outputName):
    url = "https://developer.api.autodesk.com/modelderivative/v2/designdata/job"

    headers = {
        "Authorization": "Bearer " + accessToken,
        "Content-Type": "application/json"
    }

    payload = {
        "input": {
            "urn": "urn:adsk.objects:os.object:" + bucketKey + "/" + objectName
        },
        "output": {
            "formats": [
                {
                    "type": "svf",
                    "views": ["3d"]
                }
            ],
            "destination": {
                "region": "us"
            },
            "advanced": {
                "generateMasterViews": True
            }
        }
    }

    response = requests.post(url, headers=headers, data=json.dumps(payload))

    if response.status_code == 201:
        job = response.json()
        print("Derivative job created successfully with ID: " + job["urn"])
    else:
        print("Failed to create derivative job. Error: " + response.text)

# 使用示例
accessToken = "YOUR_ACCESS_TOKEN"
bucketKey = "YOUR_BUCKET_KEY"
objectName = "YOUR_SOURCE_FILE"
outputName = "YOUR_OUTPUT_FILE"

create_derivative_job(accessToken, bucketKey, objectName, outputName)

3. 检查作业状态：可以使用以下代码示例来检查作业的状态，直到作业完成为止：

def check_job_status(accessToken, jobId):
    url = "https://developer.api.autodesk.com/modelderivative/v2/designdata/" + jobId + "/manifest"

    headers = {
        "Authorization": "Bearer " + accessToken
    }

    response = requests.get(url, headers=headers)

    if response.status_code == 200:
        manifest = response.json()
        status = manifest["status"]

        if status == "success":
            print("Derivative job completed successfully")
        elif status == "failed":
            print("Derivative job failed")
        else:
            print("Derivative job is still processing, current status: " + status)
    else:
        print("Failed to check job status. Error: " + response.text)

# 使用示例
accessToken = "YOUR_ACCESS_TOKEN"
jobId = "YOUR_JOB_ID"

check_job_status(accessToken, jobId)

4. 获取svf文件URL：一旦作业完成，可以使用以下代码示例从作业清单中获取svf文件的URL：

def get_svf_url(accessToken, jobId):
    url = "https://developer.api.autodesk.com/modelderivative/v2/designdata/" + jobId + "/manifest"

    headers = {
        "Authorization": "Bearer " + accessToken
    }

    response = requests.get(url, headers=headers)

    if response.status_code == 200:
        manifest = response.json()
        derivatives = manifest["derivatives"]

        for derivative in derivatives:
            if derivative["outputType"] == "svf":
                svfUrl = derivative["children"][0]["urn"]
                print("SVF URL: " + svfUrl)
                break
    else:
        print("Failed to get svf URL. Error: " + response.text)

# 使用示例
accessToken = "YOUR_ACCESS_TOKEN"
jobId = "YOUR_JOB_ID"

get_svf_url(accessToken, jobId)

5. 下载svf文件：最后，可以使用以下代码示例下载svf文件：

def download_svf_file(accessToken, svfUrl, outputFilePath):
    url = "https://developer.api.autodesk.com/modelderivative/v2/designdata/" + svfUrl

    headers = {
        "Authorization": "Bearer " + accessToken
    }

    response = requests.get(url, headers=headers, stream=True)

    if response.status_code == 200:
        with open(outputFilePath, 'wb') as file:
            for chunk in response.iter_content(chunk_size=