Transform matrix

[Anonymous]

Hello,

I'm having trouble understanding the Transform class and how I can obtain the internal 3x4 transform matrix.  Is it as simple as grabbing the 3 Basis vectors (i.e. the first 3 columns of the matrix), and the Origin (the 4th column of the matrix)?

Note: I have actually tried this and it mostly works, but I'm running into issues specifically with mirrored/facingflipped elements.  Am I missing something?  For example, do I need to check Transform.HasReflection and do something to the matrix?  Similarly, do the basis vectors contain the scale, or do I need to scale them using the Scale property?

Many thanks for your time,

George

[Anonymous]

Hello,

I'm having trouble understanding the Transform class and how I can obtain the internal 3x4 transform matrix.  Is it as simple as grabbing the 3 Basis vectors (i.e. the first 3 columns of the matrix), and the Origin (the 4th column of the matrix)?

Note: I have actually tried this and it mostly works, but I'm running into issues specifically with mirrored/facingflipped elements.  Am I missing something?  For example, do I need to check Transform.HasReflection and do something to the matrix?  Similarly, do the basis vectors contain the scale, or do I need to scale them using the Scale property?

Many thanks for your time,

George

[Anonymous]

Upon further investigation, the transform for the offending (FamilyInstance) element seems to have HasReflection=False.  The Transform looks completely identical to the one for a non-flipped/mirrored element, yet produces different results.  In other words, applying the two transforms to the same point via transform.OfPoint appears to yield different results.

Can anyone shed a bit more light on this?  Do I need to check some other properties on the FamilyInstance to get the correct matrix?

[Anonymous]

Upon further investigation, the transform for the offending (FamilyInstance) element seems to have HasReflection=False.  The Transform looks completely identical to the one for a non-flipped/mirrored element, yet produces different results.  In other words, applying the two transforms to the same point via transform.OfPoint appears to yield different results.

Can anyone shed a bit more light on this?  Do I need to check some other properties on the FamilyInstance to get the correct matrix?

[Anonymous]

Update: it seems that mirroring is never stored in the GetTransform for the FamilyInstance.  Instead, the mirrored data is actually encoded in the PolymeshTopology, which is a bit of a shame as it means a repeated object (with different mirroring/transforms) can't be reused if it is mirrored.

Any suggestions would be welcomed.

[Anonymous]

Update: it seems that mirroring is never stored in the GetTransform for the FamilyInstance.  Instead, the mirrored data is actually encoded in the PolymeshTopology, which is a bit of a shame as it means a repeated object (with different mirroring/transforms) can't be reused if it is mirrored.

Any suggestions would be welcomed.

[Anonymous]

what does the FamilyInstance..::..FacingFlipped Property say?

This is a very interesting question... hopefully someone can shed some light on it.

[Anonymous]

what does the FamilyInstance..::..FacingFlipped Property say?

This is a very interesting question... hopefully someone can shed some light on it.