I need to make some lines in a standard 2 point perspective grid, and the lines should go from vanish point A trough a point called B and end in a point called C.
I don't know where C will be at the moment but I know for sure where B will be.
So if I with a normal brush click on point A and shift click on point B I will get a straight line, but only between those two points.
What I really need is to make that line longer so I can attach a point C somewhere down that line. This can of course be done with the line tool, where I would drag the line as long as I wanted and make sure it intersected point B - but how is this done without using linetool and just a brush?
I tried this way - click on point A, shift click on point B, continue to hold down shift and drag the brush further, but that resulted in a correct line from A to B, but from B it just went horizontal straight (I knew that would happen, but I hoped :) )