View, projection and mapping 3D

first of all, I still can t completely get the difference and the duality of the View and Projection pins in the Renderer(EX9). Any pointer to some specific patch or tutorial ?
Secondly I tried for the first time to some outdoor 3D mapping on a facade, Actually it wasn t 100% 3D, let s say it was a 3D effect on a 2D surface.
My question is: which node is the best suited in this case for the projection view?
At home I usually use the Projector node but I find it somehow complicated outdoor if I just want to make a quick try. Taking all the measurements is a long taking task. I see that the Perspective series of nodes are those ones needed but which one exactly? Isn t there a way to pass Homography before Perspective ?
tx Simone


Have a look to that for the world, view, projection:


ok, that starts making some sense… looks like gotta better stick to the Projector node and buy a laser measurement tool…

In case of mapping a laser is quite usefull for measurements.


Hey Simone

if what you are projecting flat and rectangular, you could just use homography to adjust the projection.


thanks but it s a bit tricky using homography cause I am trying a 3D effects where the " tops" of some boxes are staying in place while the whole world moves around, I ll fix the patch asap and post it. I could always render the whole scene and then place it on a quad but dunno if the result would be acceptable.

Ok here is the patch. The faces of the blue boxes that face you are supposed to be mapped onto windows. So you get the whole idea.
At this point I don t really know which is the best way to map for such a situation. As mentioned before I became quite confident with Homography and Projector but how is best practice in this case? maybe just rendering on a quad?

I am also rather surprised my laptop can t bear this patch when I set filling to solid, setting to wireframe then it s not sloppy anymore. Specs are Lenovo T61 with Quadro nvs140m, CPU is not hogged so I guess it is the GPU…


fachadaPARA.rar (3.3 MB)