Mesh editor. select points solely in front of the object, facing the camera

hello dearest community

i have the following problem. i’m using the mesh-editor to tag points. currently the mesh-editor tags all the points which are within the xy-rectangle i draw, the z-cordinate is basically being ignored.
i would like to tag only the points on the surface of my 3d-model, which face the camera, i. e. the visible points (in the solid “fill” mode)

cinema4d does it by default, in paraviewhttp://www.paraview.org/ you can select it as an option. according to my research it seems to be a bit complex

anyone has a secont to spend some thinking on that?
what could be the best approach?
or is there already something out there in the vvvv-world, what does what i want?

thanks a lot

Just an easy trick: add a drawfixed and apply to it the same mesh as the one you are editing. Now scale it down a bit with uniform scale and paint it black. Now you see only the points facing the camera. Beware that you may be able to still click on invisible points.

hello io.
thank you for your hint. funny, this results sort of in a contour. but as you yourself pointed out, i can still tag all the other points…

perhaps you need the cull (ex9.renderstate). with it you van select which faces you want to see (only front, back or both)

culling is a point i already thought about. i just need to get the indicies from the points that are not rendered, so i can filter them out of my selection. but how?? im really not good at these sort of math.

one filter criterion could be the distance to the camera --> take only the closest point

it should be possible to do this with Intersect (3d Mesh Ray)
i will have a try

the attached modules will be part of the next release.
put the “vvvv group” folder into the \modules folder and replace old files.

open help file for (the new) MeshEditor (EX9) and try the option Edit Front Only.
Tagging and Picking Points will only affect vertices visible for the camera.

vvvv group.zip (26.2 kB)

Hello Gregsn

thanks a thousand times for your module modification, it works like a charm, although a bit cpu-hungry as it seems. my model with around 2400 points results in a framerate of around 7 fps… uiui

thanks

hi all,
i attach my question in this post because it’s “related”. I have a patch in that i’m inside a sphere, and i can look around (like a quicktime vr). and like a qtvr i have some hotspot, so i used pickpoints(3dvector) for selecting this hotspots distributed around the sphere when the mouse rollover. now, that’s the problem. i noticed that i “rollover” the point when they are behind me too. so i need to use the “edit front only” feature. i explored the mesheditor patch, but i noticed that the visiblepoints(3d), because of it’s purpouses, needs the mesh.
In my case i don’t have a mesh, but only a spread of xyz vectors that represent the points in the space. so, how can i know the hotspots is in front of camera, for picking only that?