brucegregory Posted November 17, 2003 Share Posted November 17, 2003 I know that metaballs need to be merged with a "merge" sop in order to see their combined effect upon one another, but is there a method for automatically joining each newly created metaball into the final merge so that one can monitor the blended progress of the overall metaball model whilst constructing it? Thanks, Greg Smith Quote Link to comment Share on other sites More sharing options...
edward Posted November 17, 2003 Share Posted November 17, 2003 A messy way is to bind a hotkey to the sop viewer's pane menu item: Operator > Merge Operation with All Footprints. Add a couple of metaballs (make user of the q hotkey to repeat the last operationg) and then hit your hotkey to merge them all together. Put down some more metaballs and merge them again, etc.. To edit the metaballs afterwards, put the footprint flag on your last merge sop. Now move your display sop around to each metaball sop to show its handle. Drag it around to tweak the shape. Quote Link to comment Share on other sites More sharing options...
edward Posted November 17, 2003 Share Posted November 17, 2003 Ok, here's a metaball otl replacement. It adds an "On Created" script which sets it up so that every time you put down a metaball, it will automatically merge it into the "metaball_merge" sop (automatically created if it doesn't exist). Give it a whirl by putting down metaballs in the sop viewer. Hit 'q' a couple of times to add more metaballs and see how they now automatically blend together. Unzip the attached file and put the metaball.otl file somewhere safe. Now under Houdini's File menu, choose "Install Operator Type Library". Under Operator Type Library, click on the plus button and find your OTL file. Under Install Library To:, choose $HOME/houdini6.1. Note that this was done under 6.1.179 (aka 157) and might not work with earlier versions. Finally, sorry for the non-commercial OTL as I did this from home. metaball.zip Quote Link to comment Share on other sites More sharing options...
michael Posted November 17, 2003 Share Posted November 17, 2003 neat o ! thanks ed Quote Link to comment Share on other sites More sharing options...
edward Posted November 17, 2003 Share Posted November 17, 2003 This problem has actually been bugging me ever since the new modeller got written. With all the digital asset technology that has been developed, it just suddenly became so easy to get back what the old metaball state did (er, what I remember of it anyhow ). PS. Remember to put the display (blue) flag on the final merge sop before going back up to the object level or you're gonna wonder what happened to your metaball model. Quote Link to comment Share on other sites More sharing options...
Jason Posted November 17, 2003 Share Posted November 17, 2003 Thats a great idea! Good one, Ed! Quote Link to comment Share on other sites More sharing options...
edward Posted November 17, 2003 Share Posted November 17, 2003 No prob. I guess I should mention how to un-install it too since it might get tiresome if you're trying to use metaballs for something else like deforming. Under the main menu, Tools > Operator Type Manager. In the Find Operator Definition, type in Sop/metaball. Now hit the "Current Definition Button". That should bring you to the current one selected. Click on the metaball.otl and right-click choose Uninstall. Quote Link to comment Share on other sites More sharing options...
meshsmooth Posted November 17, 2003 Share Posted November 17, 2003 Wouldn Quote Link to comment Share on other sites More sharing options...
brucegregory Posted November 17, 2003 Author Share Posted November 17, 2003 Edward: Thanks a lot, I'll give er' a whirl. One thing is still puzzling me. I went back, after writing the question on the forum, and tried laying down some more metaballs, and this time they were behaving totally differently, giving me a realtime display of the merge. I have no idea what I did to trigger this interactivity. I'm sure if I start up Master again, they will revert to their default, un-merged, spherical state. This program is deep. It is the first time I have ever felt like I can't touch the bottom. I guess something like Houdini happens when you leave a bunch of bored, smart guys in a room for a very long time, and pay them a fair wage. Greg Smith Quote Link to comment Share on other sites More sharing options...
brucegregory Posted November 17, 2003 Author Share Posted November 17, 2003 Here's what I discovered. When you start a metaball operation and follow your first metaball with a "duplicate" operator, you can continue to hit "q" for each successive metaball and they display the merge as you work. At the end of your metaball experience, you can apppend, (as they say in Houdini speak), a convert operator and turn the whole thing into a polygonal model, which, if combined with a floating viewer pane set to render polygons as subdivision surfaces, you end up with a very nice metaball modeling package with all of the other flexibilities of Houdini thrown in for free. Greg Smith Quote Link to comment Share on other sites More sharing options...
edward Posted November 18, 2003 Share Posted November 18, 2003 Ah, yes, very clever! Never occurred to me in all the years! Quote Link to comment Share on other sites More sharing options...
edward Posted November 18, 2003 Share Posted November 18, 2003 I don't get why you need to convert to polygons though. Doesn't mantra render metaballs directly? I supposed you might need to convert to polygons for motion blur but then we now have the Polygonize Metaball Procedural for that ... Quote Link to comment Share on other sites More sharing options...
deecue Posted November 18, 2003 Share Posted November 18, 2003 a convert operator and turn the whole thing into a polygonal model, which, if combined with a floating viewer pane set to render polygons as subdivision surfaces, you end up with a very nice metaball modeling package with all of the other flexibilities of Houdini thrown in for free. actually this is exactly how i modeled my fetus i am working on right now. only i used the convert metaball op rather than convert op. works much much better. the method was basically used to get a rough model of the figure and then converted to add detail. when i asked about this on the forums, i was warned about many things. and a lot of them came true i must say. such as the recooking of the metaballs and convert would occasionally change my point numbers drastically. so say when i opened the file the next day, if i had made any groups or edits then they would all be screwed. so my workaround to this was model the rough very fast in metaball. convert it. facet it to compute normals and consolidate points to ease up on it a little (also smoothed it out nicely as well). And since i would need this rough model as a start point for 16 different versions, i exported the geometry as bgeo. Now i for each version, i bring in my rough model through a file sop and do my edits and subdivides. Overall, it was decent method. Not sure if I'll go this route again, but don't regret doing it. But I did feel as if it was very sculpt-like to model a rough this way, so who knows. but then we now have the Polygonize Metaball Procedural for that ... not sure if im aware of this one...? is it new to 6.1? or are you talking about the convert meta op? Quote Link to comment Share on other sites More sharing options...
edward Posted November 18, 2003 Share Posted November 18, 2003 It was new in 6.0. Under the Render parameters page of an geo object, under the Geometry menu, change it to Procedural. In the plus button for Mantra procedural, choose Polygonized Metaballs. Quote Link to comment Share on other sites More sharing options...
brucegregory Posted November 18, 2003 Author Share Posted November 18, 2003 Edward: The reason I need to convert to polygons is for character animation. I'm not sure what happens to metaballs when you combine them with bones for animation - probably a very messy affair. Mainly, I was looking for a truly sculptural and fast way to create both basic features, (arms, legs, torso, head, fingers - and general facial details), convert to a format compatible with bones, idealize and add detail to the mesh, and, voila, the ultimately fast and efficient means to create characters. There are many aspects to this process that could surprise me, unpleasantly, later - that's the trouble with proceduralism, I guess. The one drawback I can see at this point, from a metaball standpoint, is not being able to change the individual metaball types at any point in the duplication chain. Maybe you can, but I don't yet know how. So, you are stuck with whatever metaball method you define in the beginning. You can, however still edit the placement and influence of each metaball, so it excels as a generic metaball construction set. Greg Smith Quote Link to comment Share on other sites More sharing options...
edward Posted November 19, 2003 Share Posted November 19, 2003 I wonder how the metaball modelled characters will deform though. As for metaball construction, yeah, if you go with the duplicate sop method, then you have little choice. Quote Link to comment Share on other sites More sharing options...
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