Arbitrary contour retopology

Hi

Finally I’ve made quite a breakthrough in semiautomatic retopology. What initially started as a prototype tool is evolving into a quite powerful new way to retopologize models in 3DCoat. Giving artists the freedom to experiment in an intuitive way by just drawing patches, arbitrary patches that will be optimally filled with quads.

Artist is not limited to certain number of edges , flatness or any other constraint. Just draw. I’ve also added the possibility to save and load the strokes along with the model.

The core is done, remaining now is the usability and the workflow of the tool, adding a realtime preview among other details. I’m investigating several variants and further optimizations.

I suspect this core quadrangulator algorithm will span many interesting new tools.But wait, I’m saving the real breakthrough for later 😉

PS: Could you suggest me a good (fast, high quality) screen capture program? I’ve tried CamStudio but cannot get +30fps recording  at 1080p 😦  preferably one that is HW accelerated. (using an NVIDIA GT 560M )

Cheers!

 

Arbitrary contour retopology

QuadFill tool

Hi

Finally iron out the remaining issues and is done! QuadFill is a tool aimed for quadrangulating an arbitrary 3D contours,  for testing purposes I used holes boundaries which I can easily create and shape in arbitrary forms so i can quickly test and debug the tool. But it will be used in places other than filling holes for which we ave an extensive set of algorithms. So will be more suited for retopo, autopo, and the like. The good thing is that is quite robust and flexible, given any vertex contours it will be quad dominant and produce at most, 1 triangle and the rest will be quads. Of course , that remaining triangle can be easily avoided if in a preprocess step the contour is made of even number of vertices, without loosing generality.

In previous iterations of this tool I have not addressed the complex contour case, like T-shapes, X-shapes, C, L and the like, non convex forms, causing it to fail at those:

fail1 mal2Now I have solved the general contour partition, avoiding uneven splitting, interpolating and recursive filling of each convex area. Eventually merging and smoothing/beautifying  the output mesh. Underlying steps are optimal or quasi optimal for initial contour constraints considering edge vertex are unmovable.

1 2 3

Cheers

QuadFill tool

Boundary extrusion

3DCoat currently has a powerful set of extrusion tools, you can use either voxExtrude or Bas-Relief,
both had its use cases though: VoxExtrude is for already closed mesh, you “paint” what you want to extrude, while Bas-Relief operates over the voxelized model.
But there’s a third use case: open boundaries and holes, you need to extrude and normalize.
For example in imported scanned objects from medical and technical work where they comes with holes.

Boundary extrusion

Curvature interpolation or better surface reconstruction

Hi all 🙂
Ok, this is a nice and very important feature 😉 I have improved the algorithm to make the holes reconstruction more smooth and continuous , the artist will have some control over the “smoothness” of the reconstructed mesh.
It does not aim for a “perfect” reconstruction but instead for a “good enough” reconstruction as an artist tool. The reconstruction problem is a multidimensional one that has as many solutions as researchers have the field 😉

I hope you like it!

Note: sorry for the bad screen capture, some codecs problems will solve soon 😛

Curvature interpolation or better surface reconstruction