This is the episode 0 of a series on a photogrammetry project that involves the use of Blender, Meshroom, and possibly Substance Painter. This is a basic series aimed at those with little to no experience in photogrammetry.
Video Transcript
Hello everyone! This is the episode 0 of a series on a photogrammetry project that involves the use of Blender, Meshroom, and possibly Substance Painter. This is a basic series aimed at those with little to no experience in photogrammetry.
Specifically, the project will be of the Turntable type, where an object is placed on a rotating platform, and photos are taken from the front against a uniform background.
The tutorials were created using versions 4.3 and 2023 of Blender and Meshroom, respectively. The series is intended for those who have a basic understanding of Blender and Substance Painter’s interface and main tools, but Substance Painter is optional, as I will explain shortly. No prior knowledge of Meshroom is required. You’ll just need to download and install it!
As for Substance Painter, I will be using the 2019 version, back when it was still an Allegorithmic product and perpetual licenses were available. However, the tools I will be using are also present in the more recent versions of Adobe 3D Painter. In any case, the tasks I will be performing in Substance Painter, namely creating Normal Maps and generating a PBR material, can also be done in Blender, provided you are comfortable with its tools.
I created this series by taking photos without using professional or semi professional equipment. This was a deliberate choice to showcase a photogrammetry and reconstruction pipeline starting with just a smartphone, a kitchen turntable, a green cloth, a desk lamp, and a light ring.
This setup is therefore affordable, easy to replicate, and useful for getting familiar with the tools and techniques before making any investments in better equipment.
Of course, a budget friendly setup has its downsides, both in terms of photo quality and lighting, which will cause some minor issues along the way. However, I will address these issues throughout the series, giving you some insights on how to overcome them.
The object to be reconstructed, which is a walnut shell, is a common item, but it has a surface with a good amount of detail and unique features that justify the use of photogrammetry and the creation of a Low Poly version.
Throughout the various episodes, I will first show you the lighting setup and the photo capture process in detail.
Then, I will show how to set up a photogrammetry project in Meshroom using the default workflow for a turntable project.
One episode will be dedicated to using the Color Keying and Spilling nodes in Blender to remove the green background from the photos, so that we can use cleaned up, transparent images in Meshroom.
We will then see how to start the geometry reconstruction in Meshroom, adjusting elements such as the bounding box to reduce the reconstruction area and speed up the process.
The high poly version of the geometry will then be imported into Blender for an initial review and general cleanup before creating the low poly version.
Next, we will create the low poly version of the geometry in Blender. This geometry will have its own UV unwrapping and a temporary material.
The low poly geometry will then be used in Meshroom to generate a base color texture mapped onto this new geometry.
The low poly geometry will then be imported into Substance Painter to bake the Normal Map, which means creating images that transfer details from the original high poly geometry to the new low poly model. We will see how to apply the base material with the Color and Normal textures to the low poly geometry, and then how to assign plausible materials for the Roughness channel.
In Substance Painter, we will also adjust tones and lighting using various layers. Then, we will fix errors and refine the edges between UV islands using the Smudge and Clone brushes in Passthrough mode.
Once the work in Substance Painter is complete, we will export the PBR textures. These textures will then be imported into the low poly project in Blender, allowing us to apply transformations such as position, rotation, and scale to the object, bringing the project to completion.
That’s it for this series overview! See you in the next episode!