<div dir="ltr"><div>Hi,</div><div>The RTK geometry does support the description of any scan. You can just provide the 3D coordinates of each source and detector positions with the method <a href="https://www.openrtk.org/Doxygen/classrtk_1_1ThreeDCircularProjectionGeometry.html#a0fb1475ed76a28cde24fac85eae18e1e">AddProjection</a>.</div><div>All iterative reconstruction algorithms will be to use any geometry. However, there is no filtered backprojection algorithm for helical CT reconstruction. The work had been started but has been stalled for a few years now, see</div><div><a href="https://github.com/RTKConsortium/RTK/pull/418">https://github.com/RTKConsortium/RTK/pull/418</a></div><div>Simon</div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Mon, Sep 8, 2025 at 3:21 AM 胡继涛 <<a href="mailto:hujitao226@163.com">hujitao226@163.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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<span>Does RTK support helical (spiral) scanning? If so, how should it be used?
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