Cycles limitations


  1. not enough control over quality vs time
  2. not enough anti aliasing levels
  3. not enough map channel options ( I already went into this in another thread.)
  4. viewport disintegration when panning or rotating the viewport is just plain stupid. When the viewport breaks down into black dust it really is a killer for me using this, I can’t use this for real time, it doesn’t make sense because I have to switch to my other view mode to actually see how I want to compose my shot. With large architectural scenes cycles just doesn’t work and stays black or grainy too long.
    When panning or rotating the view the viewport should revert to standard shaded with textures and no isocurves then after the user composes his view the viewport can then go into the black dust.
  5. Cycles seems to be geared towards product rendering and I see large architectural scenes not doing well currently.
  6. Controls and options in weird places and with weird nomenclature that doesn’t make sense at first. One can’t merely use cycles and get a good image with the current settings not even with the high quality setting.
  7. lighting is unpredictable. Most of time images are under or overexposed.

I understand this is in wip and I do appreciate the hard work on this, just throwing this out there to let you know what I see using cycles.

ABSOLUTELY! Now that you mention it, this seems obvious instead of the annoying, discouraging, impossible to use current behavior. Even with the new Titan X nvidia card Cycles still won’t be fast enough to get to a grain-free picture in a satisfactory length of time, so what you propose is a good second choice to make working on a scene more practical.

I just remembered I have 3d coat and it has a real time render that never goes grainy or black and always shows a decent image right from the get go even during rotating etc.

I used to use lightscape with max, that approach is the best for interior I think. In lightscape you could bake the lighting into the mesh, then in max you could import the LS mesh, change textures and add animation and then render. The render would take seconds to complete and would have all advanced lighting effects like color bleed etc. Of course one had to set up the rad processing but the output is a huge time saver in the long run. I think cycles might have something like this?

Thanks for the write up. We plan to tackle the black dust problem, hopefully before the end of this year.

There are indeed many things missing.More advanced controls are planned, but we think it is best we ensure that the out-of-box experience should be as good as possible - get good quality with as few clicks as possible. Certainly there will be room for tweaking eventually - there are many settings in Cycles that can help a lot.

I am aware of problems you mention, and they certainly are on my list!


Hi Nathan,
Thanks for your reply I know this is hard work on your part, I don’t mean to offend in any way. I want to help McNeel so let me know of anything we can do to move your work forward in as pleasant a way as possible.

One thing I am finding is that I have a few older arch interior files that I striped down and only added McNeel materials or cycles materials, now one file refuses to load and crashes Rhino when loading the other works but that too gets the occasional lock up with no bug or crash dumps. If you wish I can send you the file it’s around 25 meg.

Sure, no problem. I appreciate the feedback. It is important to get, because otherwise I’ll be living in my own bubble fantasy :slight_smile:

You can send it to my by uploading it through . You can put as the recipient. It’d help if you could copy the URL to this thread in the message field. Thanks!


i am using cycles quite a lot in blender, and their solution / workaround is the ‘Render Region’: you can define an area in the viewport (usually quite small), that renders and the rest stays viewport. Important to mention that it works well as there are simple hotkeys to clear the region (full render), and (re)set the region fast.

This won’t help for a full preview of a complex scene, but usually one works on some smaller elements, e.g. floor shader, some window glass, etc. - so you can work your way sequentially through the scene.

Actually this is an indispensable tool in cycles / blender.

I have to add, i am not currently using rhino 6, so maybe its already there, but it does not seem like it according to the posts.

edit: for clarification -

also ‘sample limits’ are a nice feature (to not have you gpu run hot)

There is no border render facility implemented for Raytraced, but it shouldn’t be too hard to add eventually. I have created a YouTrack issue to track this:

Sample limits would be just different quality settings - which already (automatically) set different sample limits.


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