applying transform

[smoothumut]

Hi Marco,

I have this code and trying to change the transformation of the c2 object but I cant succeed with it.
Am I doing something wrong here, or there is a something wrong in apply_transform?

    from vedo import Cube, show, settings,LinearTransform
    settings.use_parallel_projection = True
    import numpy as np
    
    
    c1 = Cube().rotate_z(25).pos(2,1).mirror().alpha(0.5)
    c1.transform.print()  

    T = c1.transform  
 
    c2 = Cube().c('red4').wireframe().lw(10).lighting('off')

    c2.apply_transform(T)     ### this one works
 
    
    new_transform = LinearTransform()  ## or c2.transform
    np_identity = np.eye(4)
    np_identity[0][3] = 0.1
    new_transform.matrix = np_identity
    
    c2.apply_transform(new_transform, concatenate=False)
    
    show(c2, "The c2 should be close to identity!", axes=1).close()

In the code above, I have changed the np_identity little bit, otherwise apply transform skip the transormation and return itself.
Also how can I reset the object's transformation and apply a matrix to an object

Many thanks in advance

[marcomusy]

Thanks @smoothumut I have removed the concatenate kw in the master version.

from vedo import Cube, show, settings, LinearTransform
import numpy as np

settings.use_parallel_projection = True

c1 = Cube().rotate_z(25).pos(2,1).mirror().alpha(0.5)
c1.transform.print()  

T = c1.transform  

c2 = Cube().c('red4').wireframe().lw(10).lighting('off')

c2.apply_transform(T)     ### this one works

# new_transform = LinearTransform()  ## or c2.transform
np_identity = np.eye(4)
np_identity[0][3] = 0.0001
# new_transform.matrix = np_identity

c2.apply_transform(T.compute_inverse()).apply_transform(np_identity)

show(c2, "The c2 should be close to identity!", axes=1).close()

the best way to undo a transformation is to make a copy of the original object. Otherwise you may invert the transformation and apply this inverse.

[smoothumut]

Thank you very much Marco,
It helped a lot 👍
Have a great day