Distance Along Surface¶
This effect computes shortest distance along surface to given area(s) on the mesh. You can imagine this as heating some part of the mesh to glowing red temperature, this effect computes how the temperature gradually changes along the surface into the cooler areas.
To use this effect, create a vertex color on your mesh and set all vertices to black. Then paint some vertices white – these will be the starting (“glowing hot”) points. It’s okay to use multiple points or even multiple “islands” on different parts of the mesh.
Output of the effect is a UV map, where the U component contains the distance.
Tip
You can then use the UV map in your shader with a color ramp to create the desired effect (a wave running along the surface, mesh gradually appearing, etc.).
Note
This is an approximation (upper bound) of the true distance – for best results, use quads and even topology. Polygons with a high aspect ratio or sudden changes in point density may cause artifacts (the distance will appear longer than it really is).
- Input
polygonal mesh (with color attribute)
- Output
polygonal mesh (with UV map)
- VTK classes
vtkStaticCellLinks- Preserves topology
Yes
- Multithreaded
Yes (only building topology)
Options¶
- Normalize distance
If this option turned on, computed distance in the U component will be scaled to [0;1] range. This is a safe default, suitable for cases when you don’t need to match distances across multiple objects.
If this option is turned off, the U component will be set to the actual distance along surface (as computed from local model coordinates). This makes distances comparable across objects. Note that this will generally cause the U component to have values greater than 1.0, which may cause problems in your 3D application.
