Well, i've managed to project my texture to plane, like in example (actual.png).
As i understand example, we render to texture needed objects from point of light and blend this shadow texture with our "receiver object"
Now i'm stuck how to get projection like in "needed.png" where i need to project given image to another object to given point.
I was speaking of "rayStart" - now i'm understand it's the position where "image source" located (like a light source in shadow example)
"rayEnd" - position of center of our resulting projection, "rayUp" - defines rotation.
To be more clear, i want to get the result like on this image
https://worldoftanks.ru/dcont/fb/image/wot_object_268_1024x600_noc_ru.jpgI have a model of tank, and the red star is projected like a decal to the texture. And position of this decal is defined by 3 vectors mentioned above.