CTScanVisualiser is a very minimal and rough Unity package that generates a 3D Texture from a series of CT scans and turns them into a volume of particles using VFX Graph. Notes:

• Tested with Unity 2021 LTS HDRP on a gaming laptop equipped with an NVIDIA RTX 3080 graphics card.
• The sample CT scan images are from a DICOM dataset provided freely by Medimodel for education and research, if you find them useful please share their page (https://medimodel.com/sample-dicom-files/).

• Import the Unity package inside a project.

Once imported open the scene named "CT" to explore its contents. The hiearchy should have the following gameobjects:

• Texture3DGenerator - When active and after hitting Play, this gameobject has a script attached (Scripts/TextureArrayGenerator) that generates a 3D texture in the root of the Assets folder using images from a source folder which name can be specified in the Inspector as well as image resolution and total count.

• Texture3D_VFXGraph - This gameobject relies on a VFX asset (VFX/VolumetricCT) to generate a volume of particles which colours are sampled from the 3D texture generated in the previous step. You can link a newly generated 3D Texture in the Properties section of the Inspector window.

• Texture3D_Shader - As an alternative to using a particle system (VFX Graph), this gameobject uses a shader (Shaders/VoumeShader) to render the 3D texture in the scene. The shader is a direct copy of the sample script found in the Unity documentation at https://docs.unity3d.com/Manual/class-Texture3D.html.

When used in combination with the Unity Virtual Camera app, you can use a compatible iOS device to "slice" through the volume of particles by moving the device.

• 80 Level article including full video sequence: https://80.lv/articles/turning-an-ipad-into-a-ct-scan-data-analyzer-using-unity/
• Unity Virtual Camera manual: https://docs.unity.cn/Packages/[email protected]/manual/virtual-camera.html

Notes:

• Source images must all be of the same size when generating a 3D Texture.
• Tested with 88 256x256 images on a gaming laptop equipped with an NVIDIA RTX 3080 graphics card.
• The memory impact of 3D Texture increses rapidly based on the image resolution.
• Increasing the image resolution can drastically affect performance when rendering the volume of particles (VFX Graph).
• Use the 3D Texture alone instead of the volume of particles (VFX Graph) for better performance.
• "Out-of-the-box" the included 3D Texture shader won't allow "slicing" the volume.
• Check the documentation about 3D Textures at https://docs.unity3d.com/Manual/class-Texture3D.html.