XorDrawing does a bitwise OR with the current pixel color in the viewport. So if you call it twice in a row at the same location, it will erase the previous draw call. You need to create some logic to draw it twice. Once in the last position to erase the last circle and then again at the new location to draw a new circle. It's not perfect but it gets rid of the hardware overlay drawing requirement.
On Fri, Mar 4, 2011 at 8:14 AM, Inos <ivan.ser...@gmail.com> wrote: > Hello Chad, > > (sorry for the resend, I just joined the group, and thought maybe more > people are having the same problem...) > I'm stuck for quite some time with the problem that you have solved. I > was trying to replicate the solution from the Shave & Haircut, with > the dummy transform, but I just can't find the hook for moving the > transform when the mouse moves. So, following your advice, I used Qt > (not using Python, but C++), and it works like a charm as far as > generating the mouse move events, but I have a big problem with the > actual drawing of the circle, so I was hoping you could help me out a > bit. > > I'm on a relatively cheap laptop running windows7 with a pretty > average graphics card, and the overlay drawing in the maya viewport > simply doesn't work. It either doesn't draw anything or paints the > background gray. That's why I tried using XorDrawing, but it's messing > with the maya grid and it's not consistent - sometimes the circle just > disappears. Also, when I move the cursor outside the viewport, part of > the circle remains drawn, so that's pretty bad. I would be very > grateful for any help, thanks in advance... > > Cheers, > Inos > > > On Jan 12, 11:36 pm, Chad Vernon <chadver...@gmail.com> wrote: > > I ended up using a Qt eventFilter on the viewport to capture the event > > from Qt and it seems to work fine. > > > > On Jan 11, 10:27 pm, Chad Vernon <chadver...@gmail.com> wrote: > > > > > I'm trying to replicate a brush tool much like the Artisan brush and > the > > > Shave and a Haircut brush. I have an MPxContext set up and working > fine and > > > the actual brush functionality seems to be working fine, I would just > like > > > to render the opengl red brush ring for visual feedback. I want this > to be > > > visible and follow themousearound whether themousebutton is pressed or > > > not. I scoured the docs and couldn't fine anymousemovecallback. > > > MPxContext has doPress, doDrag, doRelase, and doEnterRegion but no > plain > > >mousemove event orcallback. I noticed on Shave and a Haircut's brush > tool > > > that when you enter the context, it creates some dummy transform called > > > shaveBrushProxy that follows themousearound in the projected viewport > > > coordinates so there has to be some sort ofcallbackor hook I can use. > > > Anyone have any ideas? > > > > > Thanks, > > > Chad > > -- > http://groups.google.com/group/python_inside_maya > -- http://groups.google.com/group/python_inside_maya
