Hello everyone! I am a completely newbie to Houdini. Hope this is the right forum to post this question.

I have been playing around with the software for making an ‘Legoish’ fast explosion effect for a project. And here are the process of how I'm making it, based on watching different tutorials and combining their techniques.

To create the ‘lego’ looking mesh, I used vdbfrompolygon generating points from the fbx butterfly mesh (pic01), use box to copy, then I got the instanced blocky looking mesh(pic02).
To create the explosion, I used sphere with velocity to be the impactor hitting the blocky butterfly (RBD glued objects). see pic03.

However, the result is quiet far from what I wanna achieve. The main parts that I cannot figure out is: customize broken pieces (some are indiviual cubes some are sticked together) Right now every cube is separately ‘flying away’
I want the most hitting area (wherever the sphere hits) to have more broken pieces, whereas the corners are more sticked together (bigger pieces with cubes glued) since they get less impacted by the hit.

The ideal look of how broken pieces of the butterfly would be similar to Vladislav's roof's woodplanks in this video (from 00:23-00:28): https://vimeo.com/71811007 [vimeo.com]
As you can see the bricks are falling apart with one piece of brick or few brick ‘sticked’ together. And the each brick is still in the complete shape (not fractured) see pic04.

I also tried RBD fractured object to create the effect as well, and the hitting look is much closer to what I want. I separated the butterfly into different geometry piece in houdini (body/wings) fractured them with different fracture number and constrain strength setting so body is more fractured while wings are more stayed together. But then I wouldn't have the instanced cube geometry (I haven't succeed in copying cube to instance Lego looking geometry from original fbx with fracture basically)

I attached the houdini file (butterfly_explosion.hiplc) here, in case if you have time/want to take a look of the setup. I also put the fracture test file, to show how the ideal speed feels like.

Feels like I am having millions questions right now. Thanks for your time in advance! If there is anything confusing from the description, please let me know.