I tried with different cameras. Rotated and translated both cam and point cloud. The missing particles stays the same even if rendered from different angles. Like a boolean cut. Seems I found out whats causing it even I have no idea why it should. The ICE tree contains a 'Surface Deform'node. When disconnected everything renders ok. There was a post on the list some time ago (ICE and Mental Ray - seen anything like this?) from Chris Marshall, talking about render problems with the Slide on Surface node. The 'Surface Deform' compound I used, contains this node as well.
I may test with a demo of Arnold. But since the client wants a more stylised look, I dumped the particle approach anyway. Thanks everyone. sven -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, November 23, 2016 8:56 PM To: [email protected] Subject: Re: Particle volume rendering problem I've seen this sort of behavior as well. In my case it had to do with having camera and cube perfectly aligned -both with orientations zeroed out, or 90 degrees for instance- or the camera being close to one side of the cube, looking straight at it. Same when going from outside to inside a volume, at the moment you are intersecting the side. It's a situation you easily run into in a test setup, or when rigging the camera in certain ways. I think MR is trying to be smart and cull a few triangles intermittently (despite render settings), which messes with the volume - but that's just my interpretation. In any case, adding a very small rotation to either cube or camera, say .001 on some axis, eliminated the problem for me. It's worth a shot. (With a particle cloud the bounding box is always aligned with the world axis - so you'd have to rotate the camera) -----Original Message----- From: Morten Bartholdy Sent: Monday, November 21, 2016 10:28 AM To: [email protected] Subject: RE: Particle volume rendering problem I don't know what is going on, but it could look like bounding box issues. In Arnold and Redshift if the bounds are not set correctly for volumetrics, I get something similar, only very consistently and not random. MB > Den 18. november 2016 klokken 20:36 skrev Sven Constable > <[email protected]>: > > > sorry, broken links > > > > http://www.imagefront.de/tmp/correct_frame.JPG > > http://www.imagefront.de/tmp/problem_frame.JPG > > http://www.imagefront.de/tmp/problem_frame_w_phong.JPG > > > > > > From: [email protected] > [mailto:[email protected]] On Behalf Of Sven > Constable > Sent: Friday, November 18, 2016 8:33 PM > To: [email protected] > Subject: RE: Particle volume rendering problem > > > > Did some more tests and it looks like it's not even the shader. > Problem accours also with a standard phong. Interestingly the shape of > the cloud > changes(!) when rendered with a phong shader. > > > > some pics: > http://www.imagefront.de/tmp/correct_frame.JPG > <http://www.imagefront.de/tmp/steam_BTY.mp4> > > http://www.imagefront.de/tmp/problem_frame.JPG > <http://www.imagefront.de/tmp/steam_BTY.mp4> > > http://www.imagefront.de/tmp/problem_frame_w_phong.JPG > <http://www.imagefront.de/tmp/steam_BTY.mp4> > > > > Maybe I'll check with another renderer when I have time. > > sven > > > > From: [email protected] > [mailto:[email protected]] On Behalf Of > Schoenberger > Sent: Friday, November 18, 2016 11:32 AM > To: [email protected] > Subject: RE: Particle volume rendering problem > > > > Please reduce the lookup table size of the shader. > > See "Lookup Table" and "Setting up Lookup table": > > http://softimage.wiki.softimage.com/xsidocs/particles_shaders_Particle > Volume > ICE.htm > > > > > > > > > > Holger Schönberger > technical director > The day has 24 hours, if that does not suffice, I will take the night > > > > > > > _____ > > > From: [email protected] > [mailto:[email protected]] On Behalf Of Sven > Constable > Sent: Friday, November 18, 2016 1:57 AM > To: [email protected] > Subject: Particle volume rendering problem > > Hey list, > > > > I did some tests for an upcoming project and rendering doesn't work as > expected. Just basic ICE particles with built-in nodes and some > deformers on the pointcloud. Rendered with mental ray. > As you can see in the vid, there are render problems. Sometimes it > looks like missing tiles in the rendering but mostly it seems to be > missing particles in the cloud itself. In this video there are all > missing at the bottom but in other tests it happened also at the top > and sometime at the sides of the point cloud. Never inside the cloud. > And it only happens at render time. No particles are missing in the viewport. > > > > http://www.imagefront.de/tmp/steam_BTY.mp4 > > > > What I tried so far: > > > > Eliminated render farm problems: Rendered it locally on the workstation. > > > > Possible caching problem? Rendered it on a workstation on the fly > without any caching. > > > > Tried playback caching as well as the manual 'write cache' via the > cache manager. (unlikely since it also happens with no caching at all) > > > > Put the point cloud to global zero with no offsets in SRT. > > > > Changed most of the MR render settings. Including switching to BSP1. > Disabled On Disk Framebuffer. > > > > Changed settings of the volume shader ( specially the bounding box > size for the voxel computation. Set it to manual instead of Auto > because the missing parts always appeared at the perimeter of the > cloud). I also changed most of the other settings that possibly could > have an effect. > > > > Tried both built-in particle volume shaders, 'Particle Volume Cloud' > and the basic 'Particle Renderer'. (btw. the volume cloud shader by > Holger Schoenberger is amazing) However, it gave me the same > problems. > > > > Reduzed the particle rate (this is the video showing different > particle counts but it happens in all versions as you can see). > > > > > > I'm pretty much out of ideas. Anyone? > > > > Thanks, > > sven > > > > > > ------ > Softimage Mailing List. > To unsubscribe, send a mail to [email protected] > with "unsubscribe" in the subject, and reply to confirm. ------ Softimage Mailing List. To unsubscribe, send a mail to [email protected] with "unsubscribe" in the subject, and reply to confirm. ------ Softimage Mailing List. To unsubscribe, send a mail to [email protected] with "unsubscribe" in the subject, and reply to confirm. ------ Softimage Mailing List. To unsubscribe, send a mail to [email protected] with "unsubscribe" in the subject, and reply to confirm.
