solarain Jiao

I think it always need a lot of works on retopo after boolean, deleting some polygons, re-connecting some edges, flipping some normals, a lot of “band saws”, “multi cuts”, bevels, and so on. I believe those are not the advantages of Houdini.

I think the biggest difference about expressions between 15 and 14 is that you can't use “$+attribute name” to transfer local attribute between different nodes. Not only for those attributes added by yourself, you also cannot use local attribute such as $CY outside the copy node. They are indeed LOCAL in the new version.

Try to use @ operator instead, but unfortunately I found they sometimes doesn't work…

There are three ways that transfer local attributes from one node to another I think may work. One is to use channel expression to reference the value on the interface.

eg. ch(“surface_node/channel name”).

The second one is to use function to “read” attributes from points or primitives,

eg. points(surface_node, point_number, attrib_name, attrib_index)
or, primuv(surface_node, prim_num, attrib_name, attrib_index, u, v)

The third one is to use Bind or Parameter node, and gave them a same name to the attribute you want to cite in Attribute Vop node.

Normally when I connected a float (say, Value1) output to an int type input in VOP, the system would add an autoconvert, such as

// Code produced by: autoconvert
out_put1 = (int) Value1 ;

However, when I use while block, and make the variable in begin block as integer, and connect a float to the variable in the end block, the autoconvert doesn't added. An error message of “different type” will show up, which means I need to convert manually.

I wander if this design has some purpose or just forgetting to add a converting feature

Many thanks : )