On a standard mesh anatomical surface the vertex spacing is non-uniform across the surface. If you used the spheres you could get a uniform number of vertices (though now the patches would cover different total areas). Probably the uniform in mm approach (on the midthickness with appropriate correction for shrinkage by vertex areas) is what you want.
Peace, Matt. From: <hcp-users-boun...@humanconnectome.org<mailto:hcp-users-boun...@humanconnectome.org>> on behalf of Xinyang Liu <xinyang_ie...@163.com<mailto:xinyang_ie...@163.com>> Date: Thursday, June 7, 2018 at 8:33 AM To: HCP 讨论组 <hcp-users@humanconnectome.org<mailto:hcp-users@humanconnectome.org>> Subject: [HCP-Users] wb_command -metric-rois-from-extrema Dear HCP experts, Hi. I have some confusions when using the workbench command -metric-rois-from-extrema. When using it to draw ROIs on the fMRI surface, I found that with the same radium, the number of vertices inside the ROI can be different in different locations. For example, when r=5mm, the vertex number can range from around 30 to around 80. Maybe I do not understand very well about the parameter <limit> - geodesic distance limit from vertex, in mm. My understanding is that the distance is the radium around the extrema on the stretched surface, and the vertex numbers should be the same after the radium is set. Where do I misunderstand? Look forward to any kind guidance. Thanks a lot. Best regards, Xinyang _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org<mailto:HCP-Users@humanconnectome.org> http://lists.humanconnectome.org/mailman/listinfo/hcp-users _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users