Distorted Render

Hi, I’m using Rhino for Mac and I’m having trouble with one of my renders and need some help fixing it, I’ve tried all I know (which isn’t much) and can’t seem to find a solution.
Basically when I render my product, the image becomes distorted. The product is a display cabinet, as you can see by the attached images the inside of the cabinet looks completely different when rendered - making the cabinet appear not as deep as it actually is and distorting some of the elements inside the unit.
Never had this issue before, please help me find out how to get it to look like it does before the render!


Before Render: Curved Wall Cabinet 2019 1.pdf (4.4 MB)

After Render:

Hi Nathan,

Can you share the model with me for further investigation?

Just FYI, in Rhino WIP the render engine for Rhino Render has changed to the Cycles engine, which also is used in the Raytraced mode.


p.s. if you want to share it privately then please use rhino3d.com/upload?to=nathan@mcneel.com . I’ll be notified when the upload is complete.

Yeah that’s fine, Ive sent it over!

@mattheron, the file you sent is a v5 file. Are you using Rhino WIP (v7-to-be) or just still v5?

The glass doors are poorly constructed. I replaced the second glass door from the left with a proper extrusion, one that is properly closed.

For glass material to work as expected you need to ensure glass materials have actually two sides with thickness and that the outsides of those parts have their normals pointing outwards.

For your glass doors with rounded corners you probably can first trim them with curves, followed by maybe a loft or blend to get the caping surfaces.

Or extrude one of the surfaces so you end up with a closed surface.

I’m using v5. Just checked for updates and it says that I have the most up to date version. Is that incorrect if there’s a v7?

I’ve ended up teaching myself Rhino by just playing around with it so that might be why its not drawn massively well. Is there anything you could recommend to improve my drawing skills for making something like the cabinet you’ve seen above?

Not too sure on all the terms you’re using haha

For the glass doors I recommend you make proper closed surfaces / extrusions out of them. Say on the left most door select the glass pane (it is a group), use _Ungroup, then leave one of the big surfaces, delete the rest of the door. Extrude the one surface to the thickness you require for the door. Same for all other glass panes.

I’ll poke @pascal and @BrianJ so they can take over. I don’t know much about V5, especially not on the Mac :).

I’ll move this topic to correct category while I’m at it.

Ok will amend that, thanks for all your help Nathan :slight_smile:

Hello - as Nathan points out, if you are using glass materials with index of refraction, then a sheet of glass must have two surfaces with the thickness of the glass in between. If there is no ‘exit’ surface for the ray in the raytracing, then the glass will render as solid - as if your cabinet interior were cast in solid glass. Fully modeling both sides of the glass pane is the most realistic way to go, but for single surface glass, you can make a special ‘thin’ glass material with index of refraction (i.o.r) set to 1. (i.e. about the same as air).


In v6 and later you can select a surface and use the Thickness modifier, not sure if that exists in v5.

Changing the i.o.r seems to have done the trick, thank you very much for all your help!!

Be sure to understand how transparent materials with an IOR > 1.0 work, though. That will keep you away from surprises with such materials on single-surface objects :slight_smile: