I'm trying to optimize a particle setup process. What I want to do is a transfer the spritescale attribute from Sprite POP into SOP level. Mantra understands that right but the viewer represents sprite size incorrectly. So RFE or BUG?

Are the sprite sizes differing between the POP viewer and the SOP viewer?

I don't use Sprite POP in POPs and spritescale attribute is absent in POP level. But in SOPs spritescale attribute exists. So the default size for sprites in POPs is 1x1 and viewer represents sprites in POPs correctly. But in SOPs I see just a small… points (???) - little pieces of geometry (although spreadsheet show me spritescales from 0.1x0.1 to 100x100 and Mantra confirms that).

Are you displaying sprites? You can only view particles as sprites (not arbitrary points), and to do so you need to set the option appropriately in the Particles folder of the display options.

Are you displaying sprites?

Of course

Another thing to be aware of when creating the spritescale attribute in SOPs is that it needs to be 3 floats (even though the third component is not used).

Yep, 3 floats with third component set to 1.

* EDIT *
My bad… I use vector instead of 3 floats :? I've forgotten about that fact that vector != 3 floats and vice versa. So, now all is okay
Thanks for patience Ondrej!