Crazy Homeless Guy Posted June 19, 2003 Share Posted June 19, 2003 I have a quick question. I am new to radiosity, I have been using fakosity for seven years. I am having a problem with shadows casting when 2 objects are next to each other. I experience this the most around cabinets, and base trim. I am wondering if I need to change the modeling methods I have been using for years. Typically when I work, I construct my models in FormZ, and render them in FormZ. Now I am trying to build my models in FormZ, and render them in Max. Anyway, what I am talking about will be easier to describe with a diagram. Diagram of model in FormZ.... I typically build the walls to full height around the room, much like you would if you were physically building the space. I then go back and place my cabinets, base trim, and whatever else against the walls. When I render the scene in Max using radiosity, I get weird shadows cast off the cabinets and base trim. I am not sure if this is caused by my modeling methods, or if I just need more practice at my radiosity settings. Radiosity settings.. Initial quality.. 80.0% Refine Iterations.. 10 Filtering.. 4 Mesh size.. 5 (override of 2 on walls, soffits, floor) Thanks for any help, or anyone that can point me in the right direction.... Travis. Link to comment Share on other sites More sharing options...
ZepSOFD Posted June 26, 2003 Share Posted June 26, 2003 CHG, This is a late post and I don't know if you have found an answer yet, but it looks like shadow leaks, I could be wrong I don't have 5 yet. Having larger faces occluded by smaller objects can lead to shadow and light leaks like this, it could be something else but it wouldn't hurt to check these things. I traced your images in hot pink where faces should be trimmed away or to. Some of them I'm sure are wrong, where the object is not supposed to be touching the wall, floor, ceiling but where they do touch the face behind should be removed. tom Link to comment Share on other sites More sharing options...
Crazy Homeless Guy Posted June 27, 2003 Author Share Posted June 27, 2003 ZepSOFD... I was kind of afraid the answer was going to be something like this. Because of the way I work it will not be easy for me to trim away the faces, at least i don't think it will. I work for an architecture firm, so my models will typically go through several design studies before the final version. To make the changes painless I build my walls full height, and drop things like base trim, and casework in front of them. Usually the back faces of my object will occupy the same plane as the front face of my wall. The apps I have used for rendering in the past do not seem to mind. I don't have breakdown during rendering, because there is an object in front of the co-planar faces. I am new to 3dmax and radiosity, so I may have to change my ways. If I build my objects the way I am now, but hold the base trim, and cabinets away from the wall by 1/16th of an inch, will it fix this problem? ...I will run my own test, but probably will not have time to get to it until Monday. Thanks for the response. Link to comment Share on other sites More sharing options...
Diego Rosales Posted June 27, 2003 Share Posted June 27, 2003 Hi CHG, I don't know if it has something to do with radiosity, but I would also try lowering the shadow map bias (or ray bias, if raytraced). It could be this. Best, /Diego --EDIT-- Also make sure that you don't have coplanar faces. Many applications are picky with this kind of situation. Make the geometry intersect a bit. [ June 27, 2003, 08:01 AM: Message edited by: Diego Rosales ] Link to comment Share on other sites More sharing options...
Craig Ramsay Posted June 27, 2003 Share Posted June 27, 2003 Have you tried just moving the cabinets a tiny bit off the wall and ceiling? Craig Link to comment Share on other sites More sharing options...
Craig Ramsay Posted June 27, 2003 Share Posted June 27, 2003 Oops sorry I didn't read your post properly Moving them slightly off the wall should solve the problem Craig Link to comment Share on other sites More sharing options...
Crazy Homeless Guy Posted June 27, 2003 Author Share Posted June 27, 2003 thanks guys, i am doing some research on shadow leaks this morning. the suggestions so far sound like they will help, but i think i am going to have to spend time learning to model differently. i am used to formz, which is a solid modeler, but everything i have read today sounds like i need to focus more on modeling at the face level for radiosity. Link to comment Share on other sites More sharing options...
Craig Ramsay Posted June 27, 2003 Share Posted June 27, 2003 Absolutely! With radiosity you have to keep geometry to an absolute minimum. Craig Link to comment Share on other sites More sharing options...
Crazy Homeless Guy Posted June 27, 2003 Author Share Posted June 27, 2003 coming from a formZ background this is going to be difficult. i kind of like the way i work right now, i fear this 'new' way will be sloppy. Link to comment Share on other sites More sharing options...
ZepSOFD Posted June 27, 2003 Share Posted June 27, 2003 CHG, I hear ya about trimming faces, but if you could add an edge or vertex at/or really close to the offending area that can help in down playing any shadow or light leaks, the same holds true if you if you increase the density of your mesh(if you can afford the face count increase). Basically when there is a large contrast between 2/3's and 1/3 of a face it will most likely lead to a shadow or light leak depending on which 1/3 you are looking at(this is a basic understanding and doesn't hold true in all cases). I mostly use acad solids for modeling and I try to break faces where I know the problem will be but if I miss some, and I usually do, I start by increasing the Ref. It. either globally or by object depending on the scene. If that doesn't work I will either regather the object or fix and re-import the object. I don't think you will have any problems fixing this scene quickly, I think most can be eliminated with the Rad. Sol. settings. Hope this is useful, tom Link to comment Share on other sites More sharing options...
xgarcia Posted June 28, 2003 Share Posted June 28, 2003 Not sure because I haven't used radiosity in a while, but try the regather option. I remember that it raises your render times but it helps with shadow leaks and bad geometry (which it looks fine to me here). Lets us know if you get it to where you want it. Xavier Link to comment Share on other sites More sharing options...
Crazy Homeless Guy Posted June 30, 2003 Author Share Posted June 30, 2003 Originally posted by xgarcia: Not sure because I haven't used radiosity in a while, but try the regather option. I remember that it raises your render times but it helps with shadow leaks and bad geometry (which it looks fine to me here). Lets us know if you get it to where you want it. Xavier i started to try regather, but the amount of time added for it is scary. Link to comment Share on other sites More sharing options...
Crazy Homeless Guy Posted June 30, 2003 Author Share Posted June 30, 2003 thanks for everyone's help. i did some research on shadow leaks. i found this tutorial which does a nice job of describing shadow and light leaks, what causes them, and how to fix them. http://www.accustudio.com/forum/tutorials/modrad101.htm ___edit although the information was lifted almost word for word from a link to a .doc file on the same web site. it looks like the .doc are part of a manual for AccuRender. You have to love plagarism. I am not going to post the .doc link, the pages were probably reproduced with out consent. [ June 30, 2003, 06:53 AM: Message edited by: crazy homeless guy ] Link to comment Share on other sites More sharing options...
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