Photogrammetry and Gaussian Splats
Client:
Virginia Tech Digital Libraries
Year:
2024
Tools Used:
Agisoft Metashape • PostShot • Autodesk Maya • ZBrush • Substance 3D Painter • Substance Stager • Adobe Bridge • Canon EOS R5 Mk II • 3D Printing Tools
Overview
I currently work as a 3D Artist at the Digital Libraries and Preservation 3D Digitization (DLP) Lab at Virginia Tech, where I specialize in photogrammetry and Gaussian splat-based object digitization. Our lab produces high-fidelity 3D models for research, preservation, and teaching. We primarily use Agisoft Metashape, Substance 3D Painter, and Autodesk Maya in our workflow.
The DLP strives to capture objects as true to life as possible while preparing models to be both visually accurate and lightweight, and optimized for use in game engines, rendering software, or web-based viewers.
Relevant Links:
April 16th Egg Collection:
Vet Med Horse Clackers:
Clients & Collaborations
During my time at the DLP, I’ve collaborated with a wide range of academic departments and external partners:
VT Library Archives
– Digitization of commemorative eggs, signed sports memorabilia, and archival objects.
Department of Geosciences
– Native Virginian rocks, minerals, and crystals for educational and research use.
Virginia–Maryland College of Veterinary Medicine
– Equine bones and soft tissues for veterinary teaching materials.
Art & Architecture Library
– Digitization of unique chair designs for preservation and digital cataloging.
Upcoming Work
– Cast of Eoraptor skeleton; llama stomach preserved using a patented soft-tissue method.
These projects have ranged from small reflective objects to irregular organic specimens, each requiring tailored lighting, stabilization, and post-processing pipelines.
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Capture & Processing Workflow
1. Object Prep
We tailor our setup to each object depending on its size, stability, and surface properties.
Small objects: monopod + Syrp Genie Mini II for close-range, high-detail captures
Larger objects: Ortery turntable
Cross-polarized flash and lens filters to reduce reflections
Highly reflective or translucent objects: take photos outside or in a lightbox
2. Capture Setups
Photogrammetry:
We capture images using a Canon EOS R5 Mark II paired with a Godox AR400 Ring Flash. Both are equipped with cross-polarized filters to preserve true surface color and eliminate specular glare.
Objects are photographed on either the Ortery turntable or the Syrp Genie Mini II.
Standard capture: 4 rotations × 36 images each, rotating the object while keeping the camera fixed
Gaussian Splats:
We capture images using a Canon EOS R5 Mark II, and shoot the photos either outside or with a lightbox. This supports even lighting of the object and allows us to capture the object without a harsh flash.
Objects are photographed on either the Ortery turntable or the Syrp Genie Mini II with a lightbox surrounding it.
Standard capture: 5 rotations x 36 images each, fixed object and handheld camera
3. Adjusting RAW Photos
All images are captured in RAW and batch-edited in Adobe Bridge for both Photogrammetry and Gaussian splats.:
Standard workflow:
Applied a camera-specific color profile
Corrected white balance using a greycard shot for each object
Convert RAW to TIFF for Agisoft import
4. Processing in Agisoft Metashape
Photogrammetry:
We use Agisoft Metashape to convert our photographs into a detailed 3D mesh. The software also generates a texture for the mesh from the photos.
Standard Photogrammetry Workflow:
1. Import TIFFs
2. Generate and clean up AI masks
3. Align images
4. Solve camera positions
5. Build dense cloud and high-resolution mesh
6. Decimate mesh to create both low-poly and high-poly versions
7. Generate 8K textures for both mesh variants
8. Export low-res and high-res models as OBJ
Gaussian Splats:
We use Agisoft Metashape to assemble the camera positions and generate a point cloud of the object. Agisoft can export a .colmap file, which wraps up the edited photos, camera positions, and point cloud all in one file, preparing it for import into PostShot. (See section 6 for Postshot workflow)
Standard Gaussian Splat Workflow:
1. Import TIFFs
2. Generate AI masks
3. Align images
4. Solve camera positions
5. Export cameras as .col file
4.5. Retopology & Geometry Cleanup (Photogrammetry Only)
While most Agisoft meshes are ready for texturing, certain objects benefit from additional refinement, especially those with noisy or overly dense geometry.
Standard Retopology Workflow:
1. Import high-res model into Autodesk Maya
2. Retopologize using Maya’s Quad-Draw tool
3. Import the retopologized model into ZBrush, and the initial high-res model as well
4. Project the details of the high-res model onto the retoped model
5. Export the retoped model from ZBrush and import it into the initial Agisoft Metashape file
6. Align the new retoped model and the old Agisoft model with each other; hide the old model
7. Decimate mesh to create both low-poly and high-poly versions
8. Generate 8K textures for both mesh variants
9. Export low-res and high-res models as OBJ
5. Texture Refinement in Substance 3D Painter & Rendering in Stager (Photogrammetry Only)
We use Substance 3D Painter to bake the high-poly mesh onto the low-poly mesh so that we can make a light model that retains the high detail of the high-poly mesh. After baking, we adjust the roughness of the digital model by comparing it to the real-life object.
The final models are exported in GLB format and rendered in Substance Stager for high-quality beauty shots.
6. Processing in PostShot (Gaussian Splats Only)
We use PostShot to generate Gaussian Splats. The software exports the splats as .PLY files.
Standard Workflow:
1. Import the .col file from Agisoft Metashape
2. Set training amount
3. Clean up stray splats to reveal the model
4. Add additional training time if the model is too sparse or less detailed
5. Export as .PLY
