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Catia V5 Sweep and Spine 1
- Thread starter Webbo1981
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1
- #3
a spine curve for a swept surface is like... the base fundation of your surface.
it is used by swept surface and mutli section surface.
A good spine does usually provide a better quality surface than the default computation by CATIA.
Here you have 1 profile, it migth be planar or 3D, but let say it is planar.
if you do not define a spine, CATIA will compute one for you, easy.
if you define one, here is how it works
as I understand it.
the spine is used to define a plane.
think about a plane normal to the spine that moves along the spine.
let say your profile is on one of that plane.
and your guide curves each create only 1 intersection pt on the plane (at the extremities of your profile curve)
When the plane moves along the spine, the intersection point moves on the plane and define the new extremities for your curve (according to swept curve option)
requirements:
I like when the profile is planar, as it is a requirement for me to uderstand the result surface.
The spine curve cannot create a loop and need to have continuity in tangency. Continuity in curvature will usually give better surface...
If the profile curve is not planar or the spine curve not normal to the profile, then something is wrong, but V5 will give you a surface.
V4 will just tell you the spine is not compatible.
I like V4 better as V5 is giving me a surface I have some problem to explain.
I know about my profile, my guide but what should I use as a spine?
Make it easy, first check if a line would do the job, if not, maybe another easy planar curve, like a arc, or a spline could do the job.
If that do not work, then go for a 3D spine.
the spine will impact the result surface and isoparams
it is used by swept surface and mutli section surface.
A good spine does usually provide a better quality surface than the default computation by CATIA.
+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
Here you have 1 profile, it migth be planar or 3D, but let say it is planar.
if you do not define a spine, CATIA will compute one for you, easy.
if you define one, here is how it works
as I understand it.
the spine is used to define a plane.
think about a plane normal to the spine that moves along the spine.
let say your profile is on one of that plane.
and your guide curves each create only 1 intersection pt on the plane (at the extremities of your profile curve)
When the plane moves along the spine, the intersection point moves on the plane and define the new extremities for your curve (according to swept curve option)
requirements:
I like when the profile is planar, as it is a requirement for me to uderstand the result surface.
The spine curve cannot create a loop and need to have continuity in tangency. Continuity in curvature will usually give better surface...
If the profile curve is not planar or the spine curve not normal to the profile, then something is wrong, but V5 will give you a surface.
V4 will just tell you the spine is not compatible.
I like V4 better as V5 is giving me a surface I have some problem to explain.
I know about my profile, my guide but what should I use as a spine?
Make it easy, first check if a line would do the job, if not, maybe another easy planar curve, like a arc, or a spline could do the job.
If that do not work, then go for a 3D spine.
the spine will impact the result surface and isoparams
Eric N.
indocti discant et ament meminisse periti
indocti discant et ament meminisse periti
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