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3d_modeling:blender:clean_up_occipital_3d_scan [2020/04/06 08:12] – [Big Holes] formlab | 3d_modeling:blender:clean_up_occipital_3d_scan [2021/10/13 00:23] – [Open the file] formlab | ||
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====== Clean up a 3D scan made with the Occipital Structure scanner ====== | ====== Clean up a 3D scan made with the Occipital Structure scanner ====== | ||
- | The 3D files from the Structure scanner often have holes and unwanted geometry. After following this guide you'll get a watertight model that is ready for color-3D printing. A basic understanding of mesh manipulation in Blender is necessary. | ||
- | We will use Blender, but here is a [[3d_modeling: | ||
+ | The 3D files from the Structure scanner often have holes and unwanted geometry. After following this guide you'll get a watertight model that is ready for (colour) 3D printing. A basic understanding of mesh manipulation in Blender is necessary. | ||
+ | This guide uses Blender, but here is a [[3d_modeling: | ||
+ | |||
+ | |||
+ | ===== Open the file ===== | ||
+ | The structure scanner delivers the 3D object in 3 parts: | ||
+ | * '' | ||
+ | * '' | ||
+ | * '' | ||
+ | {{: | ||
+ | |||
+ | You only have to open the '' | ||
+ | * '' | ||
===== Setup the mesh ===== | ===== Setup the mesh ===== | ||
- | - Import the mesh. | ||
- Make the mesh active (yellow contour lines instead of orange) '' | - Make the mesh active (yellow contour lines instead of orange) '' | ||
- Right click on the mesh and select '' | - Right click on the mesh and select '' | ||
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{{: | {{: | ||
===== Join fragments to a single mesh ===== | ===== Join fragments to a single mesh ===== | ||
- | The scan data coming from the Occipital Structure sensor isn't yet joined in a single mesh. It consists of multiple sections that overlap on the edges. To test this, hover the cursor over the object and press '' | + | The scan data coming from the Occipital Structure sensor isn't yet joined in a single mesh. It consists of multiple sections that overlap on the edges. To test this, hover the cursor over the object and go to '' |
- | - Select all '' | + | - Select all: '' |
- '' | - '' | ||
- Reset normal vectors: '' | - Reset normal vectors: '' | ||
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- Add a cube. Scale and position so it overlaps with the unwanted geometry. | - Add a cube. Scale and position so it overlaps with the unwanted geometry. | ||
- Select the 3D scan mesh. | - Select the 3D scan mesh. | ||
- | - Add Boolean modifier and leave the operation as '' | + | - Add Boolean modifier and leave the operation as Difference. |
- Select the cube as the mesh to use for the boolean. | - Select the cube as the mesh to use for the boolean. | ||
- Apply the modifier. | - Apply the modifier. | ||
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Delete loose parts | Delete loose parts | ||
- | - Deselect all '' | + | - Deselect all: '' |
- | - Hover the cursor over the mesh you want to keep and press '' | + | - Hover the cursor over the mesh you want to keep and press '' |
- | - Invert the selection '' | + | - Invert the selection: '' |
- | - delete | + | - Delete |
{{: | {{: | ||
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The 3D scanner generates a mesh with messy topology. There are areas with very large faces, and others where there are lots of vertices crammed together. This creates visible stress points in the mesh. The relax function moves the vertices away from densely populated areas in order to be more equally distributed. Having the mesh relaxed will prevent a series of problems later on. This will change the shape of the mesh a little bit though. | The 3D scanner generates a mesh with messy topology. There are areas with very large faces, and others where there are lots of vertices crammed together. This creates visible stress points in the mesh. The relax function moves the vertices away from densely populated areas in order to be more equally distributed. Having the mesh relaxed will prevent a series of problems later on. This will change the shape of the mesh a little bit though. | ||
- | - select | + | - Select |
- | - Relax Vertices. A single iteration will do. '' | + | - Relax Vertices: '' |
{{: | {{: | ||
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- Select the first vertex. '' | - Select the first vertex. '' | ||
- Add the second vertex to the selection. '' | - Add the second vertex to the selection. '' | ||
- | - Merge them together. '' | + | - Merge them together: '' |
{{: | {{: | ||
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=== Fill in the gap === | === Fill in the gap === | ||
- | - fill: '' | + | - fill: '' |
{{: | {{: | ||
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New faces added to the mesh appear black or show random colours. They are referencing meaningless parts of the texture. Let's project the selected vertices to the texture and clone the surrounding texture onto that area. | New faces added to the mesh appear black or show random colours. They are referencing meaningless parts of the texture. Let's project the selected vertices to the texture and clone the surrounding texture onto that area. | ||
- | - In the '' | + | - In the UV Editing workspace, unwrap the current selection. '' |
- Scale down the selection in the UV editor and position it over a not yet textured area. | - Scale down the selection in the UV editor and position it over a not yet textured area. | ||
- | - Switch to the '' | + | - Switch to the Texture Paint workspace, Select the clone brush and set the source for the brush '' |
+ | - After drawing **save the texture image(!)**. Otherwise you'll have to redo the work. | ||
{{: | {{: | ||
==== Big Holes ==== | ==== Big Holes ==== | ||
- | When the holes are big, closing them with '' | + | When the holes are big, closing them with '' |
=== Using Grid Fill === | === Using Grid Fill === | ||
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- Select all the vertices of the edge of the hole. No selected faces are allowed. | - Select all the vertices of the edge of the hole. No selected faces are allowed. | ||
{{: | {{: | ||
- | - Fill using the ' | + | - Fill using the ' |
- Play with the Grid Fill options until a proper fit. | - Play with the Grid Fill options until a proper fit. | ||
- **Span** makes different connection patterns. | - **Span** makes different connection patterns. | ||
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Clean up dark spots by resetting the normal vectors: | Clean up dark spots by resetting the normal vectors: | ||
- | - go to '' | + | - Go to Edit Mode |
- | - select | + | - Select |
- '' | - '' | ||
- | - go back to '' | + | - Go back to object mode |
{{: | {{: | ||
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=== Fill a big hole the manual way === | === Fill a big hole the manual way === | ||
- | - Clean up the edge. Try have an even vertex distribution and a smooth edge. | + | |
+ | This is more tedious, but it allows for better control over the shape . | ||
+ | |||
+ | {{: | ||
- With the edge vertices selected, go to '' | - With the edge vertices selected, go to '' | ||
- | - Shape the n-gon by selecting opposing vertices and joining them: '' | + | - Shape the n-gon step by step by selecting opposing vertices and joining them: '' |
- | - If you need to delete elements (vertices, edges or faces), dissolve rather than delete them. '' | + | |
+ | {{: | ||
+ | Gradually defining the shape | ||
+ | |||
+ | Tips:\\ | ||
+ | - Move vertices along the edges they' | ||
+ | - Get a smoother result with proportional editing enabled | ||
+ | - If you need to delete elements (vertices, edges or faces), dissolve rather than delete them. '' | ||
Retexturing is the same as described above. | Retexturing is the same as described above. | ||
- | ===== Normals ===== | ||
- | <wrap hi>Maybe better after having a watertight object</ | + | ===== Normals ===== |
- Go to edit mode and select all vertices | - Go to edit mode and select all vertices | ||
- | - Recalculate normals: '' | + | - Recalculate normals: '' |
- | - **IMG** Show the face normals for a visual check. In Edit mode: '' | + | - If the visualisation lines are pointing inwards, select all vertices, '' |
- | - If the blue face normals | + | |
- | - **IMG** These spots are caused by split-normals that are stuck in the wrong direction. | + | |
- | - To fix this, select all vertices, '' | + | |
- | - **IMG** These problems are visually similar to the wrong facing split-normals, | + | {{: |
- | - If it's caused by vertices that are close to each other, run a [[https://docs.blender.org/ | + | Show the face normals for a visual check. In Edit mode: '' |
- | - If it's caused by a small overlap, Fix the geometry by merging some of the problematic vertices. Avoid having to make new faces, because then you'll have to redo the texture on that face. | + | |