Mechanisms for constructing spline surfaces to provide inter-surface continuity

A computer-implemented method for modifying a computer-aided design (CAD) model of a three-dimensional object, the method comprising:

• performing, by the computer:
• storing the CAD model in a memory of the computer, wherein the CAD model comprises a plurality of input surfaces comprising first and second input surfaces that cross in space along at least one intersection curve shared by the first and second input surfaces, wherein the first and second input surfaces are parametric surfaces that are described in a first and second parameter space domain, respectively;
• identifying a series of points along the at least one intersection curve;
• constructing a series of isocurves based on the identified series of points, wherein the constructed series of isocurves define a third parameter space domain;
• and
• modifying the CAD model by:
• constructing first and second output surfaces by reparametrizing the first and second input surfaces into the third parameter space domain based on the constructed series of isocurves;
• and
• replacing, in the CAD model, the first and second input surfaces with the first and second output surfaces to produce a modified CAD model of the three-dimensional object, wherein the modified CAD model exhibits increased inter-surface continuity between the first and second output surfaces relative to the first and second input surfaces.

A computer-readable memory medium comprising program instructions which, when executed by a computer, are configured to modify a computer-aided design (CAD) model of a three-dimensional object by:

• storing geometric input data describing a first and second input surface associated with the CAD model, wherein the first and second input surfaces are parametric surfaces described in a first and second parameter space domain, respectively;
• storing a model space trim curve associated with the first and second input surfaces, wherein the model space trim curve is a parametric curve that approximates a geometric intersection of the first and second input surfaces;
• reparametrizing the first and second parametric surfaces into a common third parameter space domain based on the model space trim curve;
• constructing first and second output surfaces as approximations of at least portions of the first and second input surfaces, respectively, wherein the first and second output surfaces are described in the third parameter space domain, wherein at least a portion of the boundary of each of the first and second output surfaces coincides with the model space trim curve;
• and
• storing a modified CAD model of the three-dimensional object comprising the first and second output surfaces, wherein the modified CAD model exhibits increased inter-surface continuity between the first and second output surfaces relative to the first and second input surfaces.

A computer-implemented method for modifying a computer-aided design (CAD) model of a vehicle component, the method comprising:

• performing, by the computer:
• storing geometric input data describing first and second input parametric surfaces associated with the CAD model of the vehicle component, wherein the first and second input surfaces are described in a first and second parameter space domain, respectively;
• storing a model space trim curve associated with the first and second input surfaces, wherein the model space trim curve is a parametric curve that approximates a geometric intersection of the first and second input surfaces;
• reparametrizing the first and second parametric surfaces into a common third parameter space domain based on the model space trim curve;
• constructing first and second output surfaces as approximations of at least portions of the first and second input surfaces, respectively, wherein the first and second output surfaces are described in the third parameter space domain, wherein at least a portion of the boundary of each of the first and second output surfaces coincides with the model space trim curve;
• and
• storing a modified CAD model of the vehicle component comprising the first and second output surfaces, wherein the modified CAD model exhibits increased inter-surface continuity between the first and second output surfaces relative to the first and second input surfaces;
• wherein the modified CAD model of the vehicle component is useable to design or produce the vehicle component.

A computer-implemented method for modifying a computer-aided design (CAD) model of a three-dimensional object rendered on a display, the method comprising:

• performing, by the computer:
• storing geometric input data describing first and second input parametric surfaces associated with the CAD model of the three-dimensional object, wherein the first and second input surfaces are described in a first and second parameter space domain, respectively;
• storing a model space trim curve associated with the first and second input surfaces, wherein the model space trim curve is a parametric curve that approximates a geometric intersection of the first and second input surfaces;
• reparametrizing the first and second parametric surfaces into a common third parameter space domain based on the model space trim curve;
• constructing first and second output surfaces as approximations of at least portions of the first and second input surfaces, respectively, wherein the first and second output surfaces are described in the third parameter space domain, wherein at least a portion of the boundary of each of the first and second output surfaces coincides with the model space trim curve;
• and
• storing a modified CAD model of the three-dimensional object comprising the first and second output surfaces, wherein the modified CAD model is a watertight representation of the first and second output surfaces;
• displaying on the display an animation which includes a rendering of the three-dimensional object based on the modified CAD model, wherein the rendering of the three-dimensional object based on the modified CAD model has reduced gaps along the geometric intersection of the first and second output surfaces due to the watertight representation of the first and second output surfaces.