I am looking to stop an area of a mesh being rendered. Here is the setup:
Subdivided meshgrid.
Image texture used to modify height of mesh - map grayscale onto height.
Subsurf.
Smooth.
Blender 2.56.
I want to mask part of the resulting mesh so that it is not rendered. However, using a mask modifier creates a ragged edge.
Using a knife to cut out some of the mesh is difficult as I can’t seem to find a ‘straight line’ knife tool. Also the combination of the texture resolution and the action of the subsurf also create a ragged edge.
I feel like there should be a simple solution to this problem. If anyone has any suggestions I would be very thankful.
try this, in edit mesh mode select parts you don’t want rendered, then at edit menu mesh tab and under vertices there is tool named separate (shortcut key p).
In object mode select mesh part you separated before and move it to another layer, then when you render don’t select that layer and it won’t render.
you could also setup a plane with a peephole cut out to block parts of your render.
not sure what your situation needs here but just trying to help.
As clarification, the mesh I have looks like this (this picture is from Matlab, but it is pretty much identical) and I want to diagaonally cut away so I can see ‘under’ better.
I don’t know whether this will give you want you want with your mesh, but an easy way would be to give the part you want to cut away a new material that has transparency enabled. Then set alpha to zero on this material when you want to see behind.
Thanks for the suggestion - could you give me a little guidance on how to achieve this? Here is what I tried:
Delete material (and thus teture) associated with mesh.
Select lump of vertices within mesh to quickly test.
Create new material slot - set to 0 alpha.
Click assign in the materials tab to assign the vertices to that material.
When I then press ‘select’ to select the vertices, it selects all vertices in the mesh, not just the ones I just assigned!
Also, I switched the order of the modifiers, putting subsurf first and that helped to smooth things a little when I just chop away some of the vertices.
it is no wonder now why you have jagged edges trying to cut this mesh - it will not have any
smooth cuts with mesh mathematically generated for an isosurface this way. Your best bet would be to do it mathematically, either with good knowledge and feel for isosurface equations or exploration and modification of what you have now to generate this one (kinda looks like some flow head or turbulence surface) another approach would be to use a CSG plane to cut this surface and then plot only parts < or > the plane, whichever you need.
Matlab itself has many commands for camera view direction, lighting and positioning of its output which is better than Blender for this type of feature.
