pith. sign in

arxiv: 2508.12950 · v2 · pith:KSICY4AJnew · submitted 2025-08-18 · 🧮 math.NA · cs.NA

Basis construction for polynomial spline spaces over arbitrary T-meshes

Pith reviewed 2026-05-18 22:27 UTC · model grok-4.3

classification 🧮 math.NA cs.NA
keywords T-meshesPT-splinesspline basisedge extensionlinear independencetensor-product B-splinesdiagonalizable T-meshExtended Edge Elimination
0
0 comments X

The pith

A method converts arbitrary T-meshes to diagonalizable form via edge extension, then assigns local tensor-product B-splines to each part of the dimension formula to produce a complete, linearly independent basis.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper presents the first explicit construction of basis functions for polynomial spline spaces defined over arbitrary T-meshes. It proceeds by extending edges to reach a diagonalizable T-mesh whose dimension remains stable and factors cleanly into cross-cut, ray, and T l-edge terms, then matches each term with a set of local tensor-product B-splines. A proof establishes that the resulting functions form a basis on the diagonalizable mesh. An Extended Edge Elimination step removes the added edges to recover a basis on the original mesh while preserving independence and completeness. This matters for applications that require flexible local refinement on general meshes without the independence failures seen in some earlier constructions.

Core claim

We construct spline basis functions for an arbitrary T-mesh by first converting the T-mesh into a diagonalizable one via edge extension, ensuring a stable dimension of the spline space. Basis functions over the diagonalizable T-mesh are constructed according to the three components in the dimension formula corresponding to cross-cuts, rays, and T l-edges, and each component is assigned some local tensor product B-splines as the basis functions. We prove this set of functions constitutes a basis for the diagonalizable T-mesh. To remove redundant edges from extension, we introduce a technique, termed Extended Edge Elimination (EEE) to construct a basis for an arbitrary T-mesh while reducing 0.

What carries the argument

Edge extension of an arbitrary T-mesh to a diagonalizable T-mesh whose dimension formula decomposes into independent cross-cut, ray, and T l-edge contributions, each assigned a collection of local tensor-product B-splines.

If this is right

  • The constructed functions are linearly independent and span the entire spline space on any T-mesh.
  • PT-splines apply to general T-meshes, unlike LR B-splines which require LR-meshes and may lose linear independence.
  • Dimensional instability of a spline space on a T-mesh is directly tied to degradation of the associated basis functions.
  • For certain hierarchical T-meshes the PT-spline basis outperforms the HB-spline basis in stability and completeness.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The construction could support adaptive refinement strategies in isogeometric analysis on meshes that contain arbitrary T-junction configurations.
  • The Extended Edge Elimination step might be adapted to other spline spaces defined by dimension formulas that admit similar decompositions.
  • Numerical tests on successively refined T-meshes could verify that the basis remains stable under the removal of extension edges.

Load-bearing premise

Extending edges produces a diagonalizable T-mesh whose spline-space dimension equals that of the original mesh and whose dimension formula splits cleanly into three non-overlapping contributions that can each be covered exactly by local tensor-product B-splines.

What would settle it

For a concrete arbitrary T-mesh, build the proposed basis functions, form the matrix whose columns are their coefficients in a standard monomial basis over each element, and check whether the matrix has full column rank equal to the known dimension of the spline space.

Figures

Figures reproduced from arXiv: 2508.12950 by Bingru Huang, Falai Chen, Shicong Zhong.

Figure 1
Figure 1. Figure 1: T-mesh Definition 2 ([33]) Let T be a T-mesh, with Ω denoting the region covered by its cells. The spline space over T is defined as S(d1, d2, α, β, T ) := {s(x, y) ∈ C α,β(Ω) | s(x, y)|Ci ∈ Pd1,d2 , ∀Ci ∈ T }, where Pd1,d2 is the space of bivariate polynomials of degree (d1, d2), and C α,β(Ω) is the space of bivariate functions continuous in Ω with order α in the x-direction and order β in the y-direction… view at source ↗
Figure 2
Figure 2. Figure 2: t-partition In [42], Huang et al. prove that, in a diagonalizable T-mesh, each T l-edge in the t-partition corresponds to a one-dimensional B-spline, and these edges are mutually independent. In the subsequent sections, we demonstrate that both T l-edges and rays in a diagonalizable T-mesh correspond to one-dimensional B-splines, while cross-cuts correspond to two-dimensional tensor product B-splines. 3. T… view at source ↗
Figure 3
Figure 3. Figure 3: The tensor product structure associated with v1v5 at vertices v1, v2, v4, v5. Consider a diagonalizable T-mesh. Utilizing the dimension formula (1), we derive a simplified expression as follows: ((d1 + 1 + ch)(d2 + 1 + cv)) + (nT − ((d1 + 1)th + (d2 + 1)tv)) + (nv − nT − cvch). (2) The simplified dimension formula (2) guides the partition of the diagonalizable T-mesh into three components: • The tensor pro… view at source ↗
Figure 4
Figure 4. Figure 4: The tensor product part of the T-mesh in [PITH_FULL_IMAGE:figures/full_fig_p007_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Extended T-mesh as the proof of Lemma 2 Lemma 2 demonstrates that an extended T-mesh ext(T ) can be constructed by extending the T l-edges and rays of T , satisfying the following condition [PITH_FULL_IMAGE:figures/full_fig_p008_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: The extended T-mesh which is satisfied Lemma2. • For rays in exts(T )\T(exts(T )). Lemma 3 enables the selection of exactly n(˜pi) local tensor product B-splines associated with each ray p˜i,n(˜pi) indicating the number of interior vertices on p˜i, denoted as {B ray k (x, y)} γ k=1, where γ := n ′ v − n ′ T − c ′ v c ′ h , n ′ v is the total number of interior vertices in exts(T ). Thus, the set {Bi(x, y),… view at source ↗
Figure 7
Figure 7. Figure 7: The initial T-mesh in Example 8 (a) (b) [PITH_FULL_IMAGE:figures/full_fig_p016_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: The extended T-meshes and associate local tensor product B-splines in Example 8 [PITH_FULL_IMAGE:figures/full_fig_p016_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: The support of PT-spline basis over T-mesh. (a) (b) [PITH_FULL_IMAGE:figures/full_fig_p018_9.png] view at source ↗
Figure 10
Figure 10. Figure 10: The support of LR splines over T-mesh. 4.2. Dimensional instability of spline spaces over T-meshes In this section, we utilize an example to elucidate the relationship between dimensional insta￾bility of spline spaces and PT-spline bases, offering a new perspective on this phenomenon. Example 10 Consider the T-mesh T illustrated in [PITH_FULL_IMAGE:figures/full_fig_p018_10.png] view at source ↗
Figure 11
Figure 11. Figure 11: The process to construct PT-spline basis in Example 10 [PITH_FULL_IMAGE:figures/full_fig_p019_11.png] view at source ↗
Figure 12
Figure 12. Figure 12: The PT-spline basis 8 9 B1 + B2. (a) T (b) Support of B1 (c) Support of B2 (d) Tensor product mesh [PITH_FULL_IMAGE:figures/full_fig_p019_12.png] view at source ↗
Figure 13
Figure 13. Figure 13: The process to construct PT-spline basis in Example 10. From Example 10, it is evident that the dimensional instability of spline spaces over T-meshes can be attributed to variations in the number of basis solutions of the EEE condition for T-meshes with identical topological structures but differing coordinate data [PITH_FULL_IMAGE:figures/full_fig_p019_13.png] view at source ↗
Figure 14
Figure 14. Figure 14: The example to construct PT-spline basis with T-cycle [PITH_FULL_IMAGE:figures/full_fig_p021_14.png] view at source ↗
Figure 15
Figure 15. Figure 15: The hierarchical T-mesh and the extended mesh of it. 5. Conclusion This paper presents a method for constructing basis functions for polynomial spline spaces with maximal smoothness over arbitrary T-meshes Sd1,d2 (T ). This is the first method to con￾struct basis functions for spline spaces over arbitrary T-meshes. The proposed PT-spline basis [PITH_FULL_IMAGE:figures/full_fig_p022_15.png] view at source ↗
read the original abstract

This paper presents the first method for constructing bases for polynomial spline spaces over an arbitrary T-meshes (PT-splines for short). We construct spline basis functions for an arbitrary T-mesh by first converting the T-mesh into a diagonalizable one via edge extension, ensuring a stable dimension of the spline space. Basis functions over the diagoalizable T-mesh are constructed according to the three components in the dimension formula corresponding to cross-cuts, rays, and T $l$-edges in the diagonalizable T-mesh, and each component is assigned some local tensor product B-splines as the basis functions. We prove this set of functions constitutes a basis for the diagonalizable T-mesh. To remove redundant edges from extension, we introduce a technique, termed Extended Edge Elimination (EEE) to construct a basis for an arbitrary T-mesh while reducing structural constraints and unnecessary refinements. The resulting PT-spline basis ensures linear independence and completeness, supported by a dedicated construction algorithm. A comparison with LR B-splines, which may lack linear independence and are limited to LR-meshes, highlights the PT-spline's versatility across any T-mesh. Examples are also provided to demonstrate that dimensional instability in spline spaces is related with basis function degradation and that PT-splines are advantageous over HB-splines for certain hierarchical T-meshes.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 3 minor

Summary. The paper claims to introduce the first general method for constructing bases (PT-splines) for polynomial spline spaces over arbitrary T-meshes. The construction proceeds by extending an arbitrary T-mesh to a diagonalizable one via edge extension (preserving dimension), assigning local tensor-product B-splines separately to the cross-cut, ray, and T l-edge contributions of the dimension formula, proving linear independence and completeness for the diagonalizable case, and then applying a new Extended Edge Elimination (EEE) procedure to recover a basis for the original mesh while removing redundant edges. The work includes a construction algorithm, comparisons to LR B-splines (noting their restrictions and potential lack of independence) and HB-splines, and examples linking dimensional instability to basis degradation.

Significance. If the proofs of dimension preservation under extension and linear independence after EEE are correct, the result would be significant: it supplies an explicit, algorithmically realizable basis for spline spaces on completely general T-meshes, removing the LR-mesh restriction of LR B-splines and the independence issues sometimes encountered with hierarchical constructions. The explicit decomposition into three families of local B-splines and the EEE reduction step are technically novel contributions that could be useful in isogeometric analysis and adaptive spline modeling.

major comments (2)
  1. [edge-extension construction and dimension-formula decomposition] The load-bearing step is the assertion that edge extension leaves the spline-space dimension unchanged and that the dimension formula decomposes cleanly into independent cross-cut, ray, and T l-edge contributions that can each be assigned disjoint local tensor-product B-splines. This claim appears in the construction preceding the proof for the diagonalizable mesh; if any added edge creates an unaccounted multiplicity or new T-junction not captured by the ray or l-edge count, the assigned functions will either fail to span or become linearly dependent once EEE removes the redundant edges. The manuscript must supply an explicit verification that the extension operator commutes with the dimension decomposition.
  2. [EEE procedure and final basis proof] After EEE removes the extension edges, the resulting set must still be shown to be linearly independent and complete for the original arbitrary T-mesh. The current argument relies on the diagonalizable case plus a reduction step; a concrete argument (or counter-example check) is needed showing that no new linear relations are introduced by the elimination and that the span is exactly the original space.
minor comments (3)
  1. [Abstract] The abstract contains a typographical error: 'diagoalizable' should read 'diagonalizable'.
  2. [Notation and preliminaries] Notation for T l-edges is introduced with inline math ($l$-edges) but is not consistently defined or indexed in the main text; a short notational table or paragraph would improve readability.
  3. [Comparison section] The comparison with LR B-splines would benefit from a side-by-side table listing mesh restrictions, independence guarantees, and supported T-mesh topologies.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the thorough review and constructive feedback on our manuscript. The comments correctly identify areas where the proofs would benefit from greater explicitness. We address each major comment below and will revise the manuscript to incorporate the requested clarifications and additional arguments.

read point-by-point responses
  1. Referee: [edge-extension construction and dimension-formula decomposition] The load-bearing step is the assertion that edge extension leaves the spline-space dimension unchanged and that the dimension formula decomposes cleanly into independent cross-cut, ray, and T l-edge contributions that can each be assigned disjoint local tensor-product B-splines. This claim appears in the construction preceding the proof for the diagonalizable mesh; if any added edge creates an unaccounted multiplicity or new T-junction not captured by the ray or l-edge count, the assigned functions will either fail to span or become linearly dependent once EEE removes the redundant edges. The manuscript must supply an explicit verification that the extension operator commutes with the dimension decomposition.

    Authors: We agree that an explicit verification strengthens the argument. The edge-extension procedure in Section 3 is constructed to add edges only in positions that preserve existing T-junction multiplicities and do not create new unaccounted contributions to the dimension formula. We will add a new proposition (with proof) immediately after the extension definition that shows the operator commutes with the decomposition: each added edge is classified according to whether it augments a cross-cut, ray, or T l-edge count, with a case-by-case verification that no extraneous multiplicities arise. This will be included in the revised manuscript. revision: yes

  2. Referee: [EEE procedure and final basis proof] After EEE removes the extension edges, the resulting set must still be shown to be linearly independent and complete for the original arbitrary T-mesh. The current argument relies on the diagonalizable case plus a reduction step; a concrete argument (or counter-example check) is needed showing that no new linear relations are introduced by the elimination and that the span is exactly the original space.

    Authors: The proof for the diagonalizable case (Theorem 4.1) establishes both linear independence and completeness via the disjoint assignment of local B-splines to the three dimension components. For the EEE reduction, the procedure removes only those extension edges whose associated functions are linear combinations of the retained basis functions, thereby preserving the span. We will expand the argument in Section 5 with an explicit lemma showing that EEE induces no new linear relations (by relating the elimination to the kernel of the evaluation map on the original mesh). We will also add a short computational verification subsection using the provided examples to confirm that the post-EEE functions remain independent and span the original space. revision: yes

Circularity Check

0 steps flagged

Minor self-citation to dimension formula; central construction and proof remain independent

full rationale

The derivation proceeds by mesh extension to a diagonalizable T-mesh, decomposition via a cited dimension formula into cross-cuts/rays/T l-edges, assignment of standard local tensor-product B-splines to each component, a direct proof that the resulting functions form a basis, and introduction of EEE to recover the original mesh. No step reduces a claimed prediction or basis property to a fitted parameter or to a self-referential definition within the paper itself. The dimension formula is treated as an external input whose validity is presupposed rather than re-derived here; the load-bearing novelty lies in the explicit construction algorithm and the EEE removal step, both of which are verified by direct linear-independence and spanning arguments rather than by construction from the inputs.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 1 invented entities

The construction rests on the standard dimension formula for spline spaces over T-meshes and the assumption that local tensor-product B-splines can be assigned component-wise without further parameters.

axioms (1)
  • domain assumption The dimension of the spline space over a T-mesh decomposes into independent contributions from cross-cuts, rays, and T l-edges.
    Basis functions are assigned separately to each component of this formula.
invented entities (1)
  • PT-splines no independent evidence
    purpose: Name for the constructed polynomial spline basis on arbitrary T-meshes
    New label for the output of the construction procedure; no external falsifiable prediction supplied.

pith-pipeline@v0.9.0 · 5770 in / 1319 out tokens · 41314 ms · 2026-05-18T22:27:51.361193+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

46 extracted references · 46 canonical work pages

  1. [1]

    Lin, NURBS in CAD and Computer Graphics

    F. Lin, NURBS in CAD and Computer Graphics. The University of Manchester (United Kingdom), 1996

  2. [2]

    Mixed CAD method to develop gear surfaces using the relative cutting movements and NURBS surfaces,

    F. Tolvaly-Roşca and Z. Forgó, “Mixed CAD method to develop gear surfaces using the relative cutting movements and NURBS surfaces,”Procedia Technology, vol. 19, pp. 20–27, 2015

  3. [3]

    NURBS-based and parametric-based shape optimization with differentiated CAD kernel,

    O. Mykhaskiv, M. Banović, S. Auriemma, P. Mohanamuraly, A. Walther, H. Legrand, and J.- D. Müller, “NURBS-based and parametric-based shape optimization with differentiated CAD kernel,”Computer-Aided Design and Applications, vol. 15, no. 6, pp. 916–926, 2018

  4. [4]

    NURBS curve and surface fitting for reverse engineering,

    W. Ma and J. P. Kruth, “NURBS curve and surface fitting for reverse engineering,”The International Journal of Advanced Manufacturing Technology, vol. 14, pp. 918–927, 1998

  5. [5]

    Reverse engineering of a NURBS surface from digitized points subject to boundary conditions,

    Z. W. Yin, “Reverse engineering of a NURBS surface from digitized points subject to boundary conditions,”Computers & Graphics, vol. 28, no. 2, pp. 207–212, 2004

  6. [6]

    High-order B-spline approximation for solving time-dependent timoshenko vibrating equations,

    A. B. Abdellah, S. Belkouz, and M. Addam, “High-order B-spline approximation for solving time-dependent timoshenko vibrating equations,”Wave Motion, p. 103518, 2025

  7. [7]

    Representation of 3D environment map using B- splinesurfacewithtwomutuallyperpendicularLRFs,

    R. J. Yan, J. Wu, J. Y. Lee, and C. S. Han, “Representation of 3D environment map using B- splinesurfacewithtwomutuallyperpendicularLRFs,” Mathematical Problems in Engineering, vol. 2015, no. 1, p. 690310, 2015

  8. [8]

    Path planning and replanning for mobile robot navigation on 3D terrain: An approach based on geodesic,

    K. L. Wu, T. J. Ho, S. A. Huang, K. H. Lin, Y. C. Lin, and J. S. Liu, “Path planning and replanning for mobile robot navigation on 3D terrain: An approach based on geodesic,” Mathematical Problems in Engineering, vol. 2016, no. 1, p. 2539761, 2016

  9. [9]

    Reconstruction for gated dynamic cardiac pet imaging using a tensor product spline basis,

    J. Verhaeghe, Y. D’Asseler, S. Staelens, S. Vandenberghe, and I. Lemahieu, “Reconstruction for gated dynamic cardiac pet imaging using a tensor product spline basis,”IEEE Transactions on Nuclear Science, vol. 54, no. 1, pp. 80–91, 2007

  10. [10]

    Parametric shape representation by a deformable NURBS model for cardiac functional measurements,

    S. Chen and Q. Guan, “Parametric shape representation by a deformable NURBS model for cardiac functional measurements,”IEEE Transactions on Biomedical Engineering, vol. 58, no. 3, pp. 480–487, 2010

  11. [11]

    I. J. Schoenberg, “Contributions to the problem of approximation of equidistant data by analytic functions. part b. on the problem of osculatory interpolation. a second class of analytic approximation formulae,”Quarterly of Applied Mathematics, vol. 4, no. 2, pp. 112–141, 1946. REFERENCES 24

  12. [12]

    Multivariable curve interpolation,

    J. Ferguson, “Multivariable curve interpolation,”Journal of the ACM (JACM), vol. 11, no. 2, pp. 221–228, 1964

  13. [13]

    De Boor and C

    C. De Boor and C. De Boor,A practical guide to splines. springer New York, 1978, vol. 27

  14. [14]

    T-splines and T-nurccs,

    T. W. Sederberg, J. Zheng, A. Bakenov, and A. Nasri, “T-splines and T-nurccs,”ACM trans- actions on graphics (TOG), vol. 22, no. 3, pp. 477–484, 2003

  15. [15]

    Polynomial splines over locally refined box- partitions,

    T. Dokken, T. Lyche, and K. F. Pettersen, “Polynomial splines over locally refined box- partitions,”Computer Aided Geometric Design, vol. 30, no. 3, pp. 331–356, 2013

  16. [16]

    Polynomial splines over hierarchical T-meshes,

    J. Deng, F. Chen, X. Li, C. Hu, W. Tong, Z. Yang, and Y. Feng, “Polynomial splines over hierarchical T-meshes,”Graphical models, vol. 70, no. 4, pp. 76–86, 2008

  17. [17]

    Hierarchical B-spline refinement,

    D. R. Forsey and R. H. Bartels, “Hierarchical B-spline refinement,” inProceedings of the 15th annual conference on Computer graphics and interactive techniques, 1988, pp. 205–212

  18. [18]

    THB-splines: The truncated basis for hierarchical splines,

    C. Giannelli, B. Jüttler, and H. Speleers, “THB-splines: The truncated basis for hierarchical splines,”Computer Aided Geometric Design, vol. 29, no. 7, pp. 485–498, 2012

  19. [19]

    T-spline simplification and local refinement,

    T. W. Sederberg, D. L. Cardon, G. T. Finnigan, N. S. North, J. Zheng, and T. Lyche, “T-spline simplification and local refinement,”ACM transactions on graphics (TOG), vol. 23, no. 3, pp. 276–283, 2004

  20. [20]

    Watertight trimmed NURBS,

    T. W. Sederberg, G. T. Finnigan, X. Li, H. Lin, and H. Ipson, “Watertight trimmed NURBS,” ACM Transactions on Graphics (TOG), vol. 27, no. 3, pp. 1–8, 2008

  21. [21]

    Isogeometric analysis: approximation, stability and error estimates for h-refined meshes,

    Y. Bazilevs, L. Beirao da Veiga, J. A. Cottrell, T. J. Hughes, and G. Sangalli, “Isogeometric analysis: approximation, stability and error estimates for h-refined meshes,”Mathematical Models and Methods in Applied Sciences, vol. 16, no. 07, pp. 1031–1090, 2006

  22. [22]

    Isogeometric analysis using T-splines,

    Y. Bazilevs, V. M. Calo, J. A. Cottrell, J. A. Evans, T. J. R. Hughes, S. Lipton, M. A. Scott, and T. W. Sederberg, “Isogeometric analysis using T-splines,”Computer methods in applied mechanics and engineering, vol. 199, no. 5-8, pp. 229–263, 2010

  23. [23]

    Adaptive isogeometric analysis by local h-refinement with T-splines,

    M. R. Dörfel, B. Jüttler, and B. Simeon, “Adaptive isogeometric analysis by local h-refinement with T-splines,”Computer methods in applied mechanics and engineering, vol. 199, no. 5-8, pp. 264–275, 2010

  24. [24]

    Isogeometric finite element data structures based on bézier extraction of T-splines,

    M. A. Scott, M. J. Borden, C. V. Verhoosel, T. W. Sederberg, and T. J. Hughes, “Isogeometric finite element data structures based on bézier extraction of T-splines,”International Journal for Numerical Methods in Engineering, vol. 88, no. 2, pp. 126–156, 2011

  25. [25]

    Linear independence of the T-spline blending functions associated with some particular T-meshes,

    A. Buffa, D. Cho, and G. Sangalli, “Linear independence of the T-spline blending functions associated with some particular T-meshes,”Computer Methods in Applied Mechanics and Engineering, vol. 199, no. 23-24, pp. 1437–1445, 2010

  26. [26]

    On linear independence of T-spline blending functions,

    X. Li, J. Zheng, T. W. Sederberg, T. J. Hughes, and M. A. Scott, “On linear independence of T-spline blending functions,”Computer Aided Geometric Design, vol. 29, no. 1, pp. 63–76, 2012

  27. [27]

    Local refinement of analysis-suitable T-splines,

    M. A. Scott, X. Li, T. W. Sederberg, and T. J. Hughes, “Local refinement of analysis-suitable T-splines,”Computer Methods in Applied Mechanics and Engineering, vol. 213, pp. 206–222, 2012

  28. [28]

    Analysis-suitable T-splines: Characterization, refineability, and ap- proximation,

    X. Li and M. A. Scott, “Analysis-suitable T-splines: Characterization, refineability, and ap- proximation,”Mathematical Models and Methods in Applied Sciences, vol. 24, no. 06, pp. 1141–1164, 2014

  29. [29]

    Surface modeling with polynomial splines over hierarchical T-meshes,

    X. Li, J. Deng, and F. Chen, “Surface modeling with polynomial splines over hierarchical T-meshes,”The Visual Computer, vol. 23, pp. 1027–1033, 2007. REFERENCES 25

  30. [30]

    Isogeometric anal- ysis using polynomial splines over hierarchical T-meshes for two-dimensional elastic solids,

    N. Nguyen-Thanh, H. Nguyen-Xuan, S. P. A. Bordas, and T. Rabczuk, “Isogeometric anal- ysis using polynomial splines over hierarchical T-meshes for two-dimensional elastic solids,” Computer Methods in Applied Mechanics and Engineering, vol. 200, no. 21-22, pp. 1892–1908, 2011

  31. [31]

    Adaptive isogeometric analysis using rational PHT- splines,

    P. Wang, J. Xu, J. Deng, and F. Chen, “Adaptive isogeometric analysis using rational PHT- splines,”Computer-Aided Design, vol. 43, no. 11, pp. 1438–1448, 2011

  32. [32]

    On the completeness of hierarchical tensor-product B-splines,

    D. Mokriš, B. Jüttler, and C. Giannelli, “On the completeness of hierarchical tensor-product B-splines,”Journal of Computational and Applied Mathematics, vol. 271, pp. 53–70, 2014

  33. [33]

    Dimensions of spline spaces over T-meshes,

    J. Deng, F. Chen, and Y. Feng, “Dimensions of spline spaces over T-meshes,”Journal of Computational and Applied Mathematics, vol. 194, no. 2, pp. 267–283, 2006

  34. [34]

    The structural characterization and interpolation for multivariate splines,

    R. H. Wang, “The structural characterization and interpolation for multivariate splines,”Acta Math. Sinica, vol. 18, no. 2, pp. 91–106, 1975

  35. [35]

    Multivariate spline functions and their applications,

    R. Wang, “Multivariate spline functions and their applications,”Mathematics and Its Appli- cations, vol. 529, 2001

  36. [36]

    On the dimension of spline spaces on planar T-meshes,

    B. Mourrain, “On the dimension of spline spaces on planar T-meshes,”Mathematics of Com- putation, vol. 83, no. 286, pp. 847–871, 2014

  37. [37]

    New proof of dimension formula of spline spaces over T-meshes via smoothing cofactors,

    Z. Huang, J. Deng, Y. Feng, and F. Chen, “New proof of dimension formula of spline spaces over T-meshes via smoothing cofactors,”Journal of Computational Mathematics, pp. 501–514, 2006

  38. [38]

    On the instability in the dimension of splines spaces over T-meshes,

    X. Li and F. Chen, “On the instability in the dimension of splines spaces over T-meshes,” Computer Aided Geometric Design, vol. 28, no. 7, pp. 420–426, 2011

  39. [39]

    On the problem of instability in the dimensions of spline spaces over T-meshes with T-cycles,

    Q. Guo, R. Wang, and C. Li, “On the problem of instability in the dimensions of spline spaces over T-meshes with T-cycles,”Journal of Computational Mathematics, pp. 248–262, 2015

  40. [40]

    On the stability of the dimensions of spline spaces with highest order of smoothness over T-meshes,

    B. Huang and F. Chen, “On the stability of the dimensions of spline spaces with highest order of smoothness over T-meshes,”Journal of Computational and Applied Mathematics, vol. 441, p. 115681, 2024

  41. [41]

    On the dimension of spline spaces over T-meshes with smoothing cofactor- conformality method,

    X. Li and J. Deng, “On the dimension of spline spaces over T-meshes with smoothing cofactor- conformality method,”Computer Aided Geometric Design, vol. 41, pp. 76–86, 2016

  42. [42]

    A preliminary study on the dimensional stability classification of polynomial spline spaces over T-meshes,

    B. Huang and F. Chen, “A preliminary study on the dimensional stability classification of polynomial spline spaces over T-meshes,” Submitted to arXiv, under review, 2025, arXiv submission ID: submit/6692402

  43. [43]

    Some properties of LR-splines,

    A. Bressan, “Some properties of LR-splines,”Computer Aided Geometric Design, vol. 30, no. 8, pp. 778–794, 2013

  44. [44]

    Adaptive refinement with locally linearly in- dependent LR B-splines: Theory and applications,

    F. Patrizi, C. Manni, F. Pelosi, and H. Speleers, “Adaptive refinement with locally linearly in- dependent LR B-splines: Theory and applications,”Computer Methods in Applied Mechanics and Engineering, vol. 369, p. 113230, 2020

  45. [45]

    Linear dependence of bivariate minimal support and locally refined B-splines over LR-meshes,

    F. Patrizi and T. Dokken, “Linear dependence of bivariate minimal support and locally refined B-splines over LR-meshes,”Computer aided geometric design, vol. 77, p. 101803, 2020

  46. [46]

    A hierarchical approach to adap- tive local refinement in isogeometric analysis,

    A. V. Vuong, C. Giannelli, B. Jüttler, and B. Simeon, “A hierarchical approach to adap- tive local refinement in isogeometric analysis,”Computer Methods in Applied Mechanics and Engineering, vol. 200, no. 49-52, pp. 3554–3567, 2011