Blender Technical Director

BTD/Modul 2: Übungen

Aufgabe 1: Automatisiertes Asset-Erzeugungsskript

Parametrisches Objekt erzeugen (z.B. Würfel oder Zylinder).
Parameter: Größe, Segmente, Materialzuweisung.
Objekte automatisch in einer neuen Collection organisieren.

Aufgabe 2: Custom Operator und Panel

Erstellen Sie einen Blender Custom Operator, der Objekte verschiebt.
Panel hinzufügen, das Parameter anzeigt (z.B. Verschiebe-Distanz).
Bonus: Undo-Funktion implementieren.

Aufgabe 3: Batch Rendering

Script zum Rendern aller Szenen im Blend-File erstellen.
Jede Szene in einem eigenen Unterordner speichern.
Logging: Dateipfade und Renderzeiten in Konsole ausgeben.

Material

Virtuelle Kamera in Blender

Websocket-Client: https://btd.kalisz.co/demos/2_lab_virtualcamera.html
NOTE: Browsers can only access the sensors on https://. If using TLS, you need to make sure that the Websockets are also using wss://, but for this the websocket server needs to be secured as well. This is a common pitfall!
NOTE: Another pitfall is that you need to accept the websocket certificate in the browser by navigating to the websocket server using https://, so navigate the browser to https://{IP_OF_BLENDER_SERVER:PORT} and accept the self-signed certificate.

Python: Generate SSL-Certificates

import os
import datetime
from cryptography import x509
from cryptography.x509.oid import NameOID
from cryptography.hazmat.primitives import hashes, serialization
from cryptography.hazmat.primitives.asymmetric import rsa

def generate_self_signed_cert(cert_path, key_path, hostname="localhost"):
    key = rsa.generate_private_key(
        public_exponent=65537,
        key_size=2048,
    )

    subject = issuer = x509.Name([
        x509.NameAttribute(NameOID.COMMON_NAME, hostname),
    ])

    cert = (
        x509.CertificateBuilder()
        .subject_name(subject)
        .issuer_name(issuer)
        .public_key(key.public_key())
        .serial_number(x509.random_serial_number())
        .not_valid_before(datetime.datetime.utcnow() - datetime.timedelta(days=1))
        .not_valid_after(datetime.datetime.utcnow() + datetime.timedelta(days=365))
        .add_extension(
            x509.SubjectAlternativeName([
                x509.DNSName(hostname),
                x509.DNSName("localhost"),
            ]),
            critical=False,
        )
        .sign(key, hashes.SHA256())
    )

    with open(key_path, "wb") as f:
        f.write(
            key.private_bytes(
                serialization.Encoding.PEM,
                serialization.PrivateFormat.TraditionalOpenSSL,
                serialization.NoEncryption(),
            )
        )

    with open(cert_path, "wb") as f:
        f.write(cert.public_bytes(serialization.Encoding.PEM))


CERT_DIR = "./"
CERT_FILE = os.path.join(CERT_DIR, "imu_cert.pem")
KEY_FILE = os.path.join(CERT_DIR, "imu_key.pem")

if not os.path.exists(CERT_FILE):
    generate_self_signed_cert(CERT_FILE, KEY_FILE, hostname="0.0.0.0")

HTML/Javascript: Websocket-Client

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>IMU &#8594; Blender WebSocket Controller</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">

<style>
body {
  font-family: Arial, sans-serif;
  background: #111;
  color: #eee;
  padding: 10px;
}
input, button {
  font-size: 16px;
  width: 100%;
  margin: 5px 0;
}
label {
  display: block;
  margin-top: 10px;
}
pre {
  background: #000;
  padding: 10px;
  max-height: 200px;
  overflow-y: auto;
  font-size: 12px;
}
.status {
  margin: 5px 0;
  font-weight: bold;
}
.ok { color: #0f0; }
.warn { color: #ff0; }
.err { color: #f00; }
</style>
</head>

<body>

<h2>IMU &#8594; Blender Controller</h2>

<label>
WebSocket Server (Blender):
<input id="wsUrl" placeholder="wss://192.168.178.30:8765" value="wss://192.168.178.30:8765">
</label>

<button id="connectBtn">Connect</button>

<label>
<input type="checkbox" id="useRotation" checked>
Use Rotation
</label>

<label>
<input type="checkbox" id="useTranslation" checked>
Use Translation
</label>

<div class="status" id="imuStatus"></div>
<div class="status" id="wsStatus"></div>

<h3>Debug Output</h3>
<pre id="debug"></pre>

<script>
let ws = null;
let lastData = {};

const debug = msg => {
  const el = document.getElementById("debug");
  el.textContent = msg + "\n" + el.textContent;
};

const imuStatus = document.getElementById("imuStatus");
const wsStatus = document.getElementById("wsStatus");

// --- Capability Checks ---
const hasOrientation = "DeviceOrientationEvent" in window;
const hasMotion = "DeviceMotionEvent" in window;

imuStatus.innerHTML =
  `Orientation: ${hasOrientation ? "OK" : "NO"} | Motion: ${hasMotion ? "OK" : "NO"}`;
imuStatus.className = hasOrientation ? "status ok" : "status err";

// --- iOS Permission ---
async function requestIOSPermission() {
  if (
    typeof DeviceMotionEvent !== "undefined" &&
    typeof DeviceMotionEvent.requestPermission === "function"
  ) {
    const response = await DeviceMotionEvent.requestPermission();
    debug("iOS permission: " + response);
  }
}

// --- WebSocket ---
document.getElementById("connectBtn").onclick = async () => {
  await requestIOSPermission();

  const url = document.getElementById("wsUrl").value;
  ws = new WebSocket(url);

  ws.onopen = () => {
    wsStatus.textContent = "WebSocket connected";
    wsStatus.className = "status ok";
  };

  ws.onerror = err => {
    wsStatus.textContent = "WebSocket error";
    wsStatus.className = "status err";
    debug(err);
  };

  ws.onclose = () => {
    wsStatus.textContent = "WebSocket closed";
    wsStatus.className = "status warn";
  };
};

// --- IMU Handlers ---
window.addEventListener("deviceorientation", e => {
  lastData.rotation = {
    alpha: e.alpha || 0,
    beta: e.beta || 0,
    gamma: e.gamma || 0
  };
});

window.addEventListener("devicemotion", e => {
  if (e.accelerationIncludingGravity) {
    lastData.translation = {
      x: e.accelerationIncludingGravity.x || 0,
      y: e.accelerationIncludingGravity.y || 0,
      z: e.accelerationIncludingGravity.z || 0
    };
  }
});

// --- Send Loop ---
setInterval(() => {
  if (!ws || ws.readyState !== WebSocket.OPEN) return;

  const payload = {
    useRotation: document.getElementById("useRotation").checked,
    useTranslation: document.getElementById("useTranslation").checked,
    rotation: lastData.rotation,
    translation: lastData.translation,
    timestamp: performance.now()
  };

  ws.send(JSON.stringify(payload));
  debug(JSON.stringify(payload, null, 2));
}, 30);
</script>

</body>
</html>

Blender: Websocket Server NOTE: Replace CERT_DIR = "" with your local directory where you have stored the SSL certificates (cert.pem and key.pem)