DaJuice Posted July 28, 2003 Share Posted July 28, 2003 Hi guys, I came upon a little problem during modeling that's driving me nuts. The shading of the subdivided model seems to become messed up after a merge sop in my network. First, here are a couple of views of the model with the correct shading, notice the area around the abs... Now, after I merge the forearm into the model things get weird. It's as if the model lost a lot of its definition, but the geometry has not actually changed... Also here is the display on the merge sop itself (it looks normal again after an edit sop)... I've tried everything I could think of to fix it, but no luck. I'm running Apprentice 6.0.286 on an Octane at the moment. Any help would be appreciated. Quote Link to comment Share on other sites More sharing options...
edward Posted July 28, 2003 Share Posted July 28, 2003 try facet sop and turn on orient polygons. i don't have houdini at the moment. Quote Link to comment Share on other sites More sharing options...
DaJuice Posted July 28, 2003 Author Share Posted July 28, 2003 Nope, I turn that on by default for all my facet sops. Quote Link to comment Share on other sites More sharing options...
Marc Posted July 28, 2003 Share Posted July 28, 2003 Hey there Mr Juice Firstly, I wouldn't reccommend using the orient polygons tool very much. Houdini has been known to get confused sometimes and decide to reverse polygons which really shouldn't be. If you have a problem with inverted polygons then its best to select them yourself and apply a reverse SOP. Believe me, you'll save yourself alot of headaches that way. But as for your current problem, its due to screwy normals. If you merge together different pieces of geometry and their point normals are different (for example : 1 has normals and the other doesn't, or one has them facing out and the other one facing in) then Houdini messes up the shading. So the solution for this one is simple too. Put down a facet SOP after the merge and compute the normals. This will affect the shading of the model, but it should still render correctly. I'm guessing the reason that it looks ok after an edit SOP is because the edit SOP has a 'recalculate normals' button on by default (which annoys the hell out of me BTW)... Hope this helps Marc Quote Link to comment Share on other sites More sharing options...
DaJuice Posted July 28, 2003 Author Share Posted July 28, 2003 That's exactly what I thought at first Marc, cuz that's indeed what it looks like when you merge them, but I checked and the normals are pointing outwards for all the geometry, before, during, and after the merge. I might just post up the file in a minute. Applying a facet sop and turning on pre or post compute normals makes the shading look like what I'm trying to fix. btw, I like your new title. Quote Link to comment Share on other sites More sharing options...
Marc Posted July 28, 2003 Share Posted July 28, 2003 hmm.. odd. pm me the file if you want me to take a look. Its a nice looking model btw. Good proportions. Cheers Marc P.S. After running in the wrong direction on the linux question I thought this title was appropriate Quote Link to comment Share on other sites More sharing options...
DaJuice Posted July 28, 2003 Author Share Posted July 28, 2003 Ok, sent you the file Marc. I forgot to tell you, you need to right click and save target as (geocities). Thanks. Quote Link to comment Share on other sites More sharing options...
DaJuice Posted July 29, 2003 Author Share Posted July 29, 2003 OK, I've found a way around the problem. Export the model as obj into 3d max and import it back again into Houdini as obj. Everything looks ok again. Not the ideal solution but at least I can continue working on it now. Quote Link to comment Share on other sites More sharing options...
Marc Posted July 29, 2003 Share Posted July 29, 2003 Heya ok I took a look at your file and its definitely a normals issue. The forearm prior to the merge has got point normals, while the body doesn't. I put a facet SOP down between the body and the merge and calulated normals and the shading looked right when it came through the merge. Cheers Marc Quote Link to comment Share on other sites More sharing options...
DaJuice Posted July 29, 2003 Author Share Posted July 29, 2003 I'll have to fire up the Octane and give it a shot. Thanks again. - edit - Heh, looks like you were right. Quote Link to comment Share on other sites More sharing options...
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