Making polysurfaces "lighter", too complex geometry. Urgent. HELP!

Hi everybody.

I have asked around, but nobody has the answer. I have many solids interconnected. I have used boleanUnion on it, and merge all surfaces, but the file becomes to heavy, so that i even cannot rotate if i Unhide everything.

My bachelor project depends on finding a solution to this, so I really hope some saint could help me!


The V5 tool we created for this is the Lightweight Extrusion object. However, the Boolean Union will convert them to Polysurfaces and defeat the purpose. If you drew the simple Boxes and Grouped them together so they stayed in their relative position to each other that might help but it’s an awkward use of the Group tool and may cause other unexpected frustrations.

Thank you very much for the quick answer!

I see. So there is no other way to make these polysurfaces “lighter” in any fashion or manner?

I am just searching in the dark here. I use HIDE and put select sections in LAYERS to be able to rotate, but I am afraid that when i have to RENDER, and actually use what I have made in Rhino that it will not be possible, even if I find the right CAMERA ANGLE, and do not rotate when I have UNHIDED all polysurfaces. (the file is now about 280 mb large)

Hi Adnan - MergeAllFaces may help some.


This topic comes up regulary I’ve noticed. I asked the same thing. They seem extremely reluctant to tell you this. But you need a very powerful machine to manage large complex projects.

I am hoping they will give out some more specific hardware information relative to File sizes\Project sizes in the near future.

As it currently is I can’t find anything specific.

We don’t do any specific testing along these lines to come up with these numbers. That said, there are so many different things that could effect this, it would make the testing results relatively meaningless.

Jorgen Holo, a frequent and long-time participant around here, has put together some pretty extensive performance testing tools but they are primarily focused around graphics card performance, not file size and geometry type.

I can see that. The problem is that when I try to use merge all faces on such a piece of my architecture it freezes.

It helps about 20 kb. I just tried it on a very SIMPLE geometry.

I am just astonished, that Rhino has commands for everything, but this very prominent point to be able to use the program for architecture is not solved.

Keep in mind that Rhino was never intended to be used in architecture. When we designed the basic core of the tool it was designed specifically for industrial design for things like boats, soap and perfume bottles, consumer electronics, etc. We knew then that architecture was far too big with far too demanding needs than a tiny company like ours could manage, so we intentionally avoided it.
With the advent of Grasshopper, Rhino has made some tremendous in-roads into architecture. As a result, we are playing catch up and doing lots of work to speed things up and handle larger files with coordinate ranges we never intended to support. We have a long way to go.

I really love Rhino as a tool, and will support the company. I can tell you that our schools students predominantly use Rhino for Architecture especially because of the V-ray plug-in.

If I was to use this Merge All Faces Tool and my computer freezes, does that mean that i need to use a computer with more RAM or a computer with a stronger graphic card?

Probably just too many faces. Try ExtractFace, window around a section of the object and then Join the result, then MergeAllFaces on just that bit - any luck?


I just tried it. It could work!

If I took the time to do it, but the problem is that i have about 77 pieces “just” like that on the picture, and it would take too long. But then i must see if it will be worth the time, but it is time i do not have! Unfortunately. But thank you very much for your advice!

Hi Adnan - for parts that are truly identical, consider making a Block of one and positioning copies at the other locations.


I just read about it. That could maybe work! I will try it, and get back to this thread, saying how it went.
Could be a possible solution to my problem. Now, tutorial time. I will get back to this thread. Thank you Pascal!

draw in wireframe mode when possible… ghosted is pretty much the slowest/most taxing (of the ‘normal’ drawing modes)… shaded with thin lines will be faster than ghosted… turn off isocurves… keep textures turned off when possible… keep objects which you don’t need visible turned off on separate layers.

once you’re ready to render, your main concern would be export times (and maybe memory concerns if you don’t have enough ram… rhino itself at 64bit will be able to handle it though if you have enough memory… 4-8GB should be ok… more will be better)… once it’s exported/rendering, the file size won’t really matter… you can have 1000 instances of an object in a render and it will complete around the same time as the same scene with one instance…

For a faster display - disable all isocurves. You can do by selecting all objects and disable it at the object properties or you edit your display mode.

An other way is to convert your objects to light meshes and wipe away the NURBS objects (you can keep it in a separate file). Rhino can’t right handle complex NURBS data, meshes works much better.

for much quicker display you can convert your geometry to meshes ( one of ways to do it is via ExtractRenderMesh command ) and then use Join command to make one mesh object from all of them. (make sure to delete your polysurfaces).

This will not be easily editable but as a preview or for rendering should work just fine.

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Since no one has mentioned it–for working with large files try using very coarse mesh settings. Like way coarser then “Jagged & Faster”. You’ll start to see some odd faceting, but once you get used to it you can tell what is just a display issue and what is a geometry issue. This makes editing the file much faster, and once you’re satisfied you can dial the settings back up for final renders.

Try playing around with the Density slider, and put some big values in for Minimum Edge Length and Maximum Distance Edge to Surface, then hit the preview button and see the change.