subpatch to layout problem
 

Hi, I've been using lightwave for about a week now, running into some issues sending subpatched objects from modeler into layout.

When modeling the object, using only quads, modeler renders it beautifully as a subpatched object without polygon seams. However when sending that same object to layout, everything is (automatically?) converted to triangles, which results in polygon seams and bad smoothing. Do I have a setting wrong or something? I'm attaching the screen shot examples. Modeler screen on left and layout on right.

another screenshot
 

another screenshot to show the major rendering difference, can someone tell me how to get the same modeler quality subpatched object in layout?

Try going to your surface editor and turn on the smoothing for your object. ;)

Thanks!! That fixed it. I have spent more time learning to use the tools in modeler, and I haven't done much in layout yet.

About the triangle issue... after reading on the internet I got the impression that triangles were to be avoided when modeling subpatches. it seems to me that layout is reading the quad subpatched mesh as triangles however. How are these related?

I'm not on a computer with LW right now, so I can't really check.. but in Layout, you can check the Object Properties menu, and adjust the Display/Render Subpatch levels for that object.

Right - The way subpatches work is as follows (as far as I am aware):

(1) Lightwave subdivides each polygon a number of times according to the 'Render Subpatch Level' set in layout (object properties panel). This subdivision is performed not on the base polygon, but on normals against a spline curve that touches the current mesh at the edge midpoints.

(2) Once all the subdivision is completed, Lightwave triangulates all polygons prior to rendering. It does this since the polygons created during the subdivision process are probably non planar due to the shifting of new edge points away from the original mesh along curves. Since it is impossible for a three point polygon to be non-planar, this eliminates render errors caused by the subdivision process.

Mark, you're making me look bad. Hehe just kidding! Thanks for the explanation.

Erwin... Sorry mate... :D lol

Hmm, can see that Mark is a very technical person. Thats cool. :D