Metahuman Hair Issue

On some Metahuman models, you might encounter an issue where the hair does not render when you get too far from it. This is because the level of detail of your Metahuman adjusts accordingly with the distance it is away from the camera. This is called Auto LOD, and it is very common in games for optimization purposes. But it is not so Ideal if it causes issues like, so we’ll need to disable it.

To do this, click on your Metahuman model, and look for the “LODsync” component in the Details panel. There you should see the Forced LOD value set to -1, which means it is set to auto. Change that number to 0 for the highest level of detail, such that the hair will render. You can try setting it to 1 if 0 is too much for your computer to handle. If everything works out, your Metahuman’s hair should not disappear anymore.

Setting up your Metahuman

First, we must check if the Rokoko Live plugin is installed. To do this, go to Edit, Plugins, and search for the Rokoko Live plugin. If this is your first time opening the project, it should be installed but not enabled. Enable it and restart Unreal Engine to get it working.

Next, we have to check what body type our Metahuman uses. Since every Metahuman uses a different body type, we have to identify which one it is before we start setting it up. To do this, open your Metahuman’s blueprint, go to the viewport, click on any body part (preferably the hands), and check the name of the skeletal mesh in the Details panel. The naming convention of the skeletal mesh will tell us the body type.

Here are the things to look out for:

Gender

• m – Male
• f – Female
  Height
• srt – Short
• med – Medium
• tal – Tall
  Weight
• unw – Underweight
• nrw – Normalweight
• ovw – Overweight

For example, in the tutorial video, the skeletal mesh I had was named “f_srt_nrw_body”. From this, we can deduce that the Metahuman I used, had a Female, Short, Normalweight body type. And now that we know the body type, we can look for the animation blueprint that the Metahuman uses in the content browser, by opening the corresponding folders in the common folder.

Metahuman T-pose Setup

In the animation blueprint, there should be a button to open the skeleton in the top right corner. In the skeleton window, we are going to make a T-pose pose asset for the Metahuman, because the default pose for Rokoko Studio models is the T-pose, while the default pose for the Metahumans is the A-pose.

Before making the T-pose, some settings have to be changed first.

• Firstly, in the Details panel, change the preview mesh to a body mesh that has the same body type as your Metahuman. Remember, check the naming convention for the body type. Its also important that the body mesh has hands as it will help with visualizing the finger placements later.
• Secondly, change the rotation snap value to 5°. The rotations we will be adjusting will be in multiples of 5, so 5° would be the Ideal snap value.
• Lastly, go to Character, Bones, and select the “All Hierarchy” option. This will allow us to see all the joints, which we will very much need.

Here’s a quick tip: It’ll be a lot easier to navigate through the skeleton using the Skeleton Tree, instead of trying to click the joints in the viewport.

Now we can start with the T-pose. We are going to do this by zeroing-out all the rotation values of the joints that make up the shoulders, arms, hands, and fingers, and then adjusting them a little. For this part, I would recommend watching the video as it helps to have the instructions visualize.
I usually like to start on the left clavicle. We start out by zeroing-out the rotation of the clavicle, then rotating it down to the side by 90°, such that it looks like it did before. In prior tests, we found that the Metahumans had a small issue where the arms would appear to be pushed back. Although this can be easily “fixed”, by rotating the clavicle forward by about 15°.

After the clavicle, go down the hierarchy in the Skeleton Tree, and zero-out the rotation of the upper arm, lower arm, and hand. Then rotate the hand joint by 90°, such that the palm is facing the ground. After that, continue going down the hierarchy and zero-out all the joints that make up the fingers.

If you have followed the steps correctly, all the fingers should be straight, but clipping into each other with no gaps in between. So now we have to adjust the finger joints to fix that. The fingers will be adjusted in relation to the middle finger, so that means we will not have to touch the middle finger.

I usually start with the index finger. Select the index metacarpal joint, rotate it 5° away from the middle finger, go down the hierarchy to the next joint and rotate it 5° towards the middle finger to straighten it again. Repeat this for the other fingers too, but at different angles. The ring finger will be 10°, the pinky will be 20°, and the thumb will be 30°. If everything is done properly, the hand should look like this:

Now that it is all done. We will repeat all this again on the other half of the body. The only difference is the right clavicle, where If you zero-out the right clavicle, the whole right arm points down instead of up. So, you’d have to rotate it up first by 180° before continuing as per before. If everything is done properly, you should have a nice T-pose like the one in the image below.

Now, create a pose asset by going to Create Asset at the top panel, Create PoseAsset, and click Current Pose. Save the pose asset somewhere easy to find, as we will need it later.
You can reuse the pose asset for other Metahumans of the same body type.

Metahuman Animation Blueprint Setup

Now let’s move on. Go back to the animation blueprint and open the animation graph by clicking “Animgraph” on the panel to the left. In there, create a Local to Component node, a Rokoko Body Pose node, a Component to Local node, and connect them all together as per the image below. (You do not have to delete any of the old nodes)

In the Rokoko Body Pose node, enter the name of your actor that you will be using in Rokoko studio. Take note that this is case-sensitive. Then click on the Rokoko Body Pose node again and set the Bone Map Override to the bonelist that you had just downloaded earlier. Now go back to the content browser and look for the T-pose pose asset we created just now, and drag it in. Right click it, click Convert to Pose By Name, and connect it to the Local to Component node.

Now open the pose asset (you can double click the node to open it) and look for the pose name. For most people, the pose name should be “Pose_14757”, unless you’ve attempted this before. But it is still best to check for yourself. Then, go back to the animation blueprint and with the pose asset node still selected, insert the pose name in the Details panel.
Finally, compile and save the blueprint, and your metahuman should be in a T-pose now. You might get some error messages in the animation blueprint, but that’s perfectly fine. Your metahuman might also look like its head is a bit higher or lower than the rest of the body, but that’s also perfectly fine. Now the setup is complete.

Rokoko Studio Setup

For this section, Rokoko has made numerous videos and guides on setting up Rokoko Studio, so you can check those out for yourself on their website or their YouTube channel. I’ll still be briefly covering it anyways.

First, create a project and an actor profile. Ensure that it is the same as the name you used earlier in the animation blueprint. Remember to set the height of your actor to the correct height for the best results. Then connect your Smartsuit to Rokoko Studio via a USB C cable and apply Wi-Fi settings. Ensure the IP number is green before connecting. Do the same with the Smartgloves if you have them. A small issue I faced with the Smartgloves is that it would not connect unless I set the DHCP mode to Manual instead of Auto under the advanced Wi-Fi settings. Connect Rokoko Remote if you want to do facial mo-cap. And finally, pair your inputs to your actor.

Now go down to live streaming and turn on live streaming to Unreal Engine. The port number should be visible above. Keep that in mind because we will need it later.