Spliiting a flat object

[Neil_Cross]

I've ended up with this completely flat object which is 1 mesh, but I need to break it into 5 pieces essentially splitting across the red lines below.  The geometry separation tool is ineffective here as it's all on 1 plane (flat) so there's no angles to pick up on.  Is there a way to separate something like this? In something like Inventor you'd create a construction plane where the red lines are use those as split planes.

edit - I've only marked 1-3 but if using the below example it would be 5 pieces

[michael_nikelsky · Accepted solution]

Not really since we are not a modelling tool. I think the best you can do is use the Split Geometry into Triangles (assuming they are meshes) and then do rectangle selections and merge those triangles back together that you want to have as one geometry. Then hide what you have already merged and continue with the next part. 

As a tip: Remember that drawing a selection box from left to right gives you a different result as drawing it from right to left. The first will only select what is completely inside the rectangle while the second will also select objects only partially inside the selection box.

[Neil_Cross]

Thanks Michael that'll do the job.  It's a bit messy as you need super small triangles as to not get a hardcore jagged edge if the textures are different, and working with triangles that small causes Vred to lose its mind and get sleepy.  But that's a solution, thanks!