yeah you got to becareful with that when you draw…you have to remember that retopology is basically still in a BETA form…its not 100% great… and its set to a kinda stupid set up… when you draw a new line or when you have to connect a line together you have to make sure that the vertex/point you want the line to be drawn from is selected first and then go about drawing new line you have to notice which vertex your new line is going to connect to by seeing the vertex with the red circle and the white bones pointing the directions of the lines spawning from it…when you draw a new line, the line will be connected to that vertex with the red circle…what you have to do is basicaly hold shift and click the vertex you want the new line to be drawn from and then you can click to draw the next line…it gets tedicious and annoying having to hold shift, click the vertex that you want the line to connect to and then draw the new line, you also have be careful too because holding shift and holding the left mouse button can draw and gather aka “paint” the topology thats already exists on the topology…
the original setup
the way it was set up is that when you draw a new line/vertex/dot/point you will draw 3 additional lines/vertexs/dots/points before moving onto the next one.its a stupid set up…it should be that the last vertex you draw gets selected so that you can create straight lines but rather its set up to create an X shape first… so when you draw a new vertex… its made so you draw the other vertex above it and below it and then either to the left or to the right…thats basically how they created it… but you can deny the order by shift left clicking the vertex to draw the new line from and then drawing it. you will occassionally get lucky and find that you can draw a chain of straight lines but you have to study the setup and realise how the setup is