How can you match lighting in photorealistic models to original 3D scans?

1 Why is lighting important?

Lighting is a crucial element of any 3D scene, as it affects the appearance, mood, and realism of the models. Lighting can also convey information about the shape, texture, and material of the objects, as well as the time of day, weather, and location of the scene. When you scan a real-world scene, you capture the lighting conditions of that moment, but they may not match your intended use of the model. For example, you may want to use a model of a building in a different season, or a model of a person in a different environment. Therefore, you need to adjust the lighting of your model to match your desired context.

2 How to capture lighting information from 3D scans?

One way to capture lighting information from 3D scans is to use a technique called high dynamic range imaging (HDRi). HDRi is a method of combining multiple images taken at different exposure levels to create a single image that contains a wide range of brightness and color values. HDRi images can be used as environment maps or light probes to create realistic lighting effects in 3D scenes. To create HDRi images from 3D scans, you need to use a camera that can capture multiple exposures, a tripod, and a spherical mirror or a chrome ball. You can then use software tools like PTGui or Hugin to stitch the images together and create a HDRi image.

3 How to use HDRi images in 3D modeling software?

Once you have a HDRi image from your 3D scan, you can use it in your 3D modeling software to create realistic lighting for your model. Different software may have different ways of using HDRi images, but the general steps are similar. First, you need to import the HDRi image as a texture and apply it to a sphere or a dome that surrounds your model. This will create a background image that simulates the original environment. Second, you need to enable image-based lighting (IBL) or global illumination (GI) in your software settings. This will allow the HDRi image to cast light and shadows on your model. Third, you need to adjust the intensity, rotation, and scale of the HDRi image to match your model's orientation and size.

4 How to fine-tune lighting in 3D models?

Using HDRi images from 3D scans can help you create realistic lighting in 3D models, but you may still need to fine-tune some aspects of the lighting to achieve your desired results. For example, you may want to add some artificial lights, such as spotlights or point lights, to highlight certain features of your model or create dramatic effects. You may also want to tweak the color, contrast, and brightness of the HDRi image or the model's materials to match your artistic vision or the mood of the scene. You can use tools like Photoshop or Gimp to edit the HDRi image, or use the built-in features of your 3D modeling software to adjust the lighting parameters.

5 How to test lighting in 3D models?

The final step of matching lighting in photorealistic models to original 3D scans is to test the lighting in different scenarios and renderings. You can use different methods to test the lighting, such as previewing the model in different views, rendering the model in different resolutions and formats, or exporting the model to different platforms and applications. You can also compare the model to the original 3D scan or the real-world scene to check for any discrepancies or errors. The goal of testing the lighting is to ensure that the model looks realistic, consistent, and appealing in any context or situation.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?