How to Replace UV Map pass from blender in After effects

 In a previous tutorial, we exported a UV Map Pass from Blender, but exporting it alone is not enough. The main purpose of this pass is to use it outside Blender and modify it without having to re-render the scene every time.

In this article, I’ll explain the workflow that I personally use to work with a UV Map Pass inside After Effects and how to change images on a 3D object while preserving the original animation that we previously rendered. As always, I’ll explain everything step by step, so let’s get started.

What Do We Need Before We Start?

Before we begin applying this workflow inside After Effects, there are a few files that need to be prepared in advance. This tutorial is considered the second part of the article Exporting a UV Map Pass from Blender Using Eevee.

The first file we need is the UV Map Pass that we rendered from Blender. If you haven’t followed the previous tutorial, the file should be in OpenEXR format with a sample count of at least 130 to achieve a good result.

We will also need the UV layout file for the model, as well as the image or video that we want to apply to the object.

The final step is installing a plugin. There are several plugins available for this workflow; some are paid, such as ft-UVPass and RE:Map, while others are free. In this tutorial, I’ll use the free PixMap plugin developed by Wunk. Download it, install it, and restart After Effects. I chose this plugin so that everyone can follow along and benefit from the tutorial without needing to purchase additional tools.

Creating a New Composition

After opening After Effects, import the UV Map Pass file and create a new composition from it. As you can see, I renamed it to UVX. 

Next, import the UV layout file for the model. To make the tutorial easier to follow, I’ll use the same flag model that we created in a previous lesson. If you want to reproduce the exact waving flag animation, read How I Created a Waving Flag Animation in Blender  because the result will be much easier to compare and understand.

After that, create another new composition from the UV Map and rename it to keep everything organized. I named mine UV Map Footage. Then, add the image that you want to apply to the model underneath the UV layout. In my case, I’ll use several flag images, including the Algerian flag, but you can use any image that fits your project.

After adding the image, adjust its size and position so that it covers the desired area of the UV Map inside the Composition, then hide the UV grid because this is the image that will later be applied to the 3D model.

Adding the UV Pass to the Main Composition 

Once the image is prepared, add the UV Map Footage composition to the first composition, which we named UVX. You can hide it because we don’t need to see it directly; it will only be used by the plugin later to convert the image into the correct UV coordinates for the model.

This leaves only the UV Map Pass layer visible, which is the image containing the green and red gradient. Keeping only this layer visible makes the workflow much easier.

Applying the PixMap Plugin 

Now we move to the most important step in this tutorial: applying the PixMap plugin to the UV Map Pass layer.

In the UVX composition, select the UV Map Pass layer, then go to Effect → Wunk Effects → PixMap.

In the Effects Controls panel, under the Textures section of the plugin, choose the UV Map Footage composition containing the flag image as the source.

You’ll notice that the plugin doesn’t work correctly at first. The image changes, but it doesn’t appear in the correct way and looks distorted. The reason is that a few settings need to be adjusted before continuing.

Fixing the Plugin Display Issue

To fix the issue, select the UV Map Pass file in the Project panel, right-click it, choose Interpret Footage → Main, and configure the following settings:

• First, set the frame rate to match your project. In my case, I rendered the UV pass from Blender at 24 FPS.

Fixing the Plugin Not Working Correctly

To fix the issue where the image appears distorted, locate the UV Map Pass file in the Project panel. Right-click it, then choose Interpret Footage → Main. After that, adjust the following settings:

• First, set the footage frame rate to match your Blender project. In my case, I rendered the animation at 24 FPS.

• Next, open the Color Management section and enable the Preserve RGB option, then click OK to apply the changes.

After enabling this option, the image should be mapped onto the 3D model correctly. In some cases, however, it may appear slightly offset. If that happens, simply adjust the Offset values in the PixMap effect until the texture is properly aligned. In my case, no additional adjustments were necessary, as shown below.

Removing Pixel Artifacts

Once everything is working, you may notice some unwanted pixelation or jagged edges around the texture.

A simple fix is to increase your project's color depth from 8 Bits to 16 Bits or 32 Bits, provided your computer can handle it.

Replacing Images and Videos with Ease

At this point, you can replace the image with any other image you like without ever going back to Blender or rendering the scene again.

Even better, you can use videos in exactly the same way. Simply replace the image with a video, and it will be mapped directly onto the 3D model while preserving the exact animation that was previously rendered. As shown in the GIF below, this makes it incredibly easy to experiment with different textures and animated content.

This is exactly why I started using this workflow in some of my projects. It saves a significant amount of time whenever the animation stays the same and only the textures or images applied to the model need to be changed.