LightFighter Posted September 11, 2011 Share Posted September 11, 2011 Hi All, I am newbie just trying to get into Houdini, switching over from Maya. I want to be able to bring in a geometry from maya, fracture it, sim it, bring it back in maya and render with prman. Apologies if this question has already been posted, I tried the search but couldn't find any leads. I am stuck with something that should be really super easy to do, but can't seem to get my head around it . So, 1. I start with a sphere in Maya 2. Bring it in Houdini 3. Scatter points -> Feed it to a Voronoi Fracture Points -> Voronoi fracture 4. Then, RBD Fracture object 5. Everything is good, sphere falls and breaks apart. 6. Then I export that as a fbx to bring it in maya. 7. In maya, after I import that fbx, the animation is fine, although, I can't apply a "smooth" operation on it, it adds divisions but stays "sharp", retains the hard edges. ( I want to be able to render the geo as subdivs ) 8. Another problem is UV's, how can I get some form of UVs on my fractured object ? I don't need it to be a dynamic fracture. so I thought I'd be able to some how get UV's from an object created in maya, which is why I exported the sphere from maya in the first place and pre fractured using the voronoi fracture node. 9. Is it possible to export selected pieces as separate objects instead of one object ? Thanks a lot for your help! Cheers, Devank Quote Link to comment Share on other sites More sharing options...
LaidlawFX Posted September 11, 2011 Share Posted September 11, 2011 Devank!!!! Welcome to the forum man! It's Ben from school, I wish I had the time to help, but I figured I would say hi man! Quote Link to comment Share on other sites More sharing options...
ehsan parizi Posted September 11, 2011 Share Posted September 11, 2011 As long as I know, FBX does NOT support polygon groups. I'm just curious, Why don't you export the smooth geo? BTW, if you export obj's it kinda gives you the groups names, but it's not actual different geometries! it's still just 1 object.But I've done it with objs before! I'll work on it and will let you know if I can find a solution! Quote Link to comment Share on other sites More sharing options...
ehsan parizi Posted September 11, 2011 Share Posted September 11, 2011 ok! if you want to use obj, you must first get rid of all the groups that have shared members, for example, if you're using a voronoi fracture node, you need to delete outside and inside groups, and then you'll have separate objects in Maya. But I'm not sure if a sequence of obj files would be efficient for your pipeline! Quote Link to comment Share on other sites More sharing options...
LightFighter Posted September 11, 2011 Author Share Posted September 11, 2011 (edited) Devank!!!! Welcome to the forum man! It's Ben from school, I wish I had the time to help, but I figured I would say hi man! Hi Ben! Thanks! How's it going, Long time man. We gotta meet up if you are in the sf bay area! I just saw your junk ford's final version :-) looks great! nice reel ok! if you want to use obj, you must first get rid of all the groups that have shared members, for example, if you're using a voronoi fracture node, you need to delete outside and inside groups, and then you'll have separate objects in Maya. But I'm not sure if a sequence of obj files would be efficient for your pipeline! Hi Ehsan, Thanks a lot for your reply! I will definitely give it a shot, and yes it won't be that great to have a bunch of OBJ's, but maybe I can write a script that imports only one group from the DopNet and exports its animation as an fbx, just a wild idea One update though, the smooth/subdiv problem turns out to be rather simple, the faces are just not "weld"/"fused" together, like, every corner has about 4-5 vertexes. I'm attaching an image here that shows that, I just need to figure out an equivalent of "Keep faces together option" from maya in houdini. Thanks again! appreciate it Edited September 11, 2011 by LightFighter Quote Link to comment Share on other sites More sharing options...
ehsan parizi Posted September 11, 2011 Share Posted September 11, 2011 but maybe I can write a script that imports only one group from the DopNet and exports its animation as an fbx, just a wild idea One update though, the smooth/subdiv problem turns out to be rather simple, the faces are just not "weld"/"fused" together, like, every corner has about 4-5 vertexes. I'm attaching an image here that shows that, I just need to figure out an equivalent of "Keep faces together option" from maya in houdini. hmmmm, What do you mean when you say "imports only one group from the DopNet and exports its animation as an fbx"? Isn't it what you did before? because if you want to export all the geometry as one object, you can use fbx! and I personally try to do whatever I want to do to my geometry in Houdini (like smoothing and etc. ) and then export it to Maya! About the fuse problem, have you tried the fuse sop?! Quote Link to comment Share on other sites More sharing options...
LightFighter Posted September 11, 2011 Author Share Posted September 11, 2011 hmmmm, What do you mean when you say "imports only one group from the DopNet and exports its animation as an fbx"? Isn't it what you did before? because if you want to export all the geometry as one object, you can use fbx! and I personally try to do whatever I want to do to my geometry in Houdini (like smoothing and etc. ) and then export it to Maya! About the fuse problem, have you tried the fuse sop?! I meant, each piece as a separate fbx :-) Yep, I'll give fuse a shot. For smoothing, I wanted to do it at rendertime, this is a simple sphere, but what I'm trying to do is a glacier calving, and there's a LOT of geometry involved Quote Link to comment Share on other sites More sharing options...
LaidlawFX Posted September 11, 2011 Share Posted September 11, 2011 Hi Ben! Thanks! How's it going, Long time man. We gotta meet up if you are in the sf bay area! I just saw your junk ford's final version :-) looks great! nice ree I'll give you a shout the next time I come up to the bay, I've been in LA for the last year plus. Life is good swamped as s*** at work. Gona go enjoy life today and go drown in the surf, playing out the stereotypical cali surfer type. Crunch time + no upper arm strength + surfing = hysterical. What you been up to? How's life? Quote Link to comment Share on other sites More sharing options...
LightFighter Posted September 12, 2011 Author Share Posted September 12, 2011 I'll give you a shout the next time I come up to the bay, I've been in LA for the last year plus. Life is good swamped as s*** at work. Gona go enjoy life today and go drown in the surf, playing out the stereotypical cali surfer type. Crunch time + no upper arm strength + surfing = hysterical. What you been up to? How's life? Sweet!, haha nice! Life is good man, working on guardians right now at Dreamworks. Very excited for this project. Nothing new other than that! same old :-) Quote Link to comment Share on other sites More sharing options...
LightFighter Posted September 12, 2011 Author Share Posted September 12, 2011 Just an update on this, I am able to solve the smoothing problem after using the Merge vertices command based on a threshold value of how far a vertex is from the others, in maya, and this will solve the smoothing and render as subdiv problem. Although, I'd like to do this in Houdini as for something as simple as a sphere this works but when I do the actual sim, I am expecting a lot of geometry and Maya may not be able to handle all of this ? I have tried using the fuse sop in houdini with a fairly large threshold but even then when I export it to maya I am getting the same problems!! I'd appreciate it if anyone can post a solution to this and/or point me to what I'm doing wrong here! Thank you, Devank Quote Link to comment Share on other sites More sharing options...
LightFighter Posted September 13, 2011 Author Share Posted September 13, 2011 Hi all, So, finally got it working! Wanted to post it here in case anyone would like to know. I want to thank Steven Knipping (colleague at dw) for showing me the ROP Output Driver - www.stevenknipping.com It unfortunately takes a couple steps other than that though as I don't like .obj files per frame to use with maya, I prefer fbx. 1. Do your sim 2. Create a geo object -> then a dop import -> (Bring in the sim 'dopnet' in SOP) 3. Export this using a rop output driver as -> .obj files per frame 4. in your "geo" object -> create a file node to read those .obj files 5. use File -> Export as FBX and make sure you have "Detect Constant Point Count Dynamic Objects" checked ON, because this makes sure any non deforming objects, i.e. RBDs in this case will be exported as a single, smooth object with UVs, otherwise it breaks them up into triangles and you don't get UVs 6. Enjoy, now when you import that fbx in maya you get rid of the separate faces problem AND you get UV's I have attached a screenshot too. Thanks all for your help. Appreciate it Quote Link to comment Share on other sites More sharing options...
edward Posted September 15, 2011 Share Posted September 15, 2011 Shouldn't step 5 be all that is required? There should not be difference from just displaying the dopimport SOP and your file SOP? Quote Link to comment Share on other sites More sharing options...
ehsan parizi Posted September 15, 2011 Share Posted September 15, 2011 I think Edward is right! If you didn't want to have a different group for each piece, just exporting as fbx would work perfectly! I don't think exporting and importing obj files is doing anything here. Quote Link to comment Share on other sites More sharing options...
LightFighter Posted September 15, 2011 Author Share Posted September 15, 2011 Haha oh my, I have no clue what was going wrong but that is exactly what I tried atleast a million and two times! and it WOULDN'T WORK!, but now it does O_o. Although, Its good the way I did it, because then export multiple objects instead of just one for the whole scene. Will need to run a loop for the number of groups I set, import each group from the dopnet one by one and export them into objs, then read those objs one by one and export as fbx, unless of course there is an elegant way of doing it. Thanks a lot for your input!, its very much appreciated! Quote Link to comment Share on other sites More sharing options...
benne5 Posted April 26, 2014 Share Posted April 26, 2014 (edited) Hi Folks!, I am running into the same issue that Devank ran into. I am trying to export a flipfluid surface object sequence that has been cached from Houdini using FBX Filmbox to Maya 2012. I have "Detect Constant Point Count Dynamic Objects" checked on. When it is imported into Maya the geometry is unsmoothed. I would just use Alembic or another custom exporter, however I am working on a shot at work with a tight deadline and going through the proper channels to get the alembic plugin for Maya or another custom exporter could take weeks. Any ideas on how to solve my problem would be much appreciated. Thanks. Edited April 26, 2014 by benne5 Quote Link to comment Share on other sites More sharing options...
benne5 Posted April 26, 2014 Share Posted April 26, 2014 Hi Again Folks, I got it working. I needed to apply the merge function in Maya. It does the job. Unfortunately, it greatly slows down Maya when attempting to scrub through the animation after the merge functionality is applied. It is great to have this much functioning. Quote Link to comment Share on other sites More sharing options...
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