V6 material preview flicker and obj import problems

I just installed the latest Rhino wip out today, Work In Progress (6.0.16264.10331, 9/20/2016) Beta

I noticed that the materials tab has a terrible flash to it and the screen redraws of materials gets slower and slower as I work on a file, changing settings in a material. I noticed that just clicking an object and looking at it’s material there is a noticeable flicker in the material tab, sometimes I see numeric code displayed flashing if I click on another material or change a setting. The flicker is a pretty intense strobe like a 2-3 second vibe.

I am exporting .obj files from max using the Rhino obj file settings in max. Nice by the way Autodesk recognizes McNeel now and I can work import and export obj files not having to worry about scaling and placement. The scene in max has night lighting I notice now all my materials are really dark when I open the exported obj file in Rhino when displayed in the viewport in my custom mode or in any mode with lighting on. The only way to get my materials brighter is to add a light and up its value to 200 percent or to turn off material filtering in the bitmap slot of the material. then the material displays properly lit In my viewport mode.

For instance if I create a copy material I noticed I had to turn filtering off so that the bitmap of the material could display at it’s proper value otherwise all materials in the file I am working on are coming in really dark. A black and white image comes in as a shaded dark gray.

Then I could not drag and drop a copy of a material on an object and have that object retain the new material’s settings, it always reverted to the default material and not the copied material I created, which was a material with filtering = off maybe a bug there? I then clicked on options and Rhino crashed.

Prior to that Rhino V6 was constantly crashing trying to import any obj file. I’ve been in 3dsmax so I haven’t used Rhino in the last few weeks but do have the latest builds at least the current build allowed me to import object files. It was funny rhino crashed several times as I fed it different obj files then a message update available and I updated and low and behold obj file import works now. I noticed that the raytrace viewport seems a bit faster? Thanks for the hard work and getting these betas out to us.


I was able to repeat and fix a great deal of unnecessary flickering, but I did not see the ‘2-3 second vibe’ or the increasing slowdown. Does this slowdown occur over minutes or many hours? The ‘numeric code’ problem is a known issue which I intend to fix as soon as I can figure out how to repeat it on my machine.

The fixes I made today should appear in the next WIP.


Hi John,
I noticed that in my case it might be due to importing the obj file and checking layers in the obj import options. This imports a lot of layers and I think might have effected the material areas causing a slow down, I notice if I check object names instead there are less layers created and I don’t get the problems as badly. I still get the flicker but it’s not as pronounced.

One other minor thing I can’t reproduce if I import obj file as layers was that choosing the option drop down in the color picker on a material caused Rhino to freeze, I had to use task manager to shut rhino off, it happened 3 times. This is where I saw the numeric code flash.

Thanks for looking into this I’ll try to see if I can narrow it down and find the exact cause. Also thanks for the Rhino obj export option out of 3dstudio max don’t know if that option matters or not on import or if that’s McNeel’s doing but its nice to have.

It’s possible that there is a ‘material slow-down’ related to having lots and lots of layers. I will look into that. But apart from that, there is no (deliberate) connection between the Material Editor and the OBJ import function. They are totally separate systems maintained by different developers. I’m personally only responsible for the material stuff. It’s possible that there is some kind of unexpected interaction between them but I’m not sure how it could happen. However, any information or clues you can give are always helpful.