Jump to content

BIM Viewport line rendering - Extremely slow

Recommended Posts

Good afternoon everyone, 

I have a fairly serious situation when i recently decided to go about creating an existing 5 story building in vectorworks. The model is pretty large, approximately  405 megabytes. It contains 7 floor plates - including a cellar and a roof plan, but other than that it isn't that complex. I did include plumbing and sinks in 3d as well as 3d cabinets and countertops for kitchens on most of the floors. The existing building is a substantially a brick building, so i decided to use a brick hatch and texture for the surface perimeter. the opengl 3d model is pretty responsive, it takes a little bit of time to preload the 3d elements, but after that its very easy to navigate. The problem is this - the wireframe renderings for elevations take extremely long, in fact impossibly long to render and i cannot figure out why. In previous versions i haven't had this problem on 4 - 5 story buildings, but i also didn't have as many objects in it either. My question is this - could this be a memory leak? or just incorrect method of approaching the project? or perhaps not enough hardware specs? Listing my hardware specs below:

Windows 7 sp1

Intel Core i7 - 5820k @ 3.3 ghz (can overclock to 4)

Ram - 16 Gb - Dual channel ddr @ 1200 mhz

Motherboard - Asrock x99 Extreme 4

Graphics - Nvidia Geforce GTX 1060 - 6 gb

Main HD - crucial 250 bx100 ssd drive (operating system, temp storage)

Storage HD - Seagate 2 tb harddrive - 7200 rpm


If its hardware - what do you suppose the bottleneck is ? Hint - could it be the ram? I checked the usage while rendering - and it jumped to 16 gb (my max). But does it really need that much ram in order to render line renderings from a BIM model? and 2 - why does it preload ALL the objects in back of the facade when they're not shown? Isn't that a bit counter productive? (at least it seems that way - from a logical standpoint)

I could post the file - but let me know, its 400 mb


Thank you in advance everyone !

Link to comment



I think i solved the problem. By eliminating the classes you don't need, it doesn't preload that geometry. Just a note for the future for everyone - Be careful how you load you classes when you render a model. 

Also create a limited depth for the rendering to further increase speed!

Although I still think there should be some way to eliminate preloading automatically for elevations. I will limit the items rendered in the future though. 
Hope this gives some people a heads up!

Link to comment
26 minutes ago, Samuel Derenboim said:

The problem is this - the wireframe renderings for elevations take extremely long, in fact impossibly long to render and i cannot figure out why.


Your hardware is pretty current and ok.


With wireframe rendering do you mean hidden line rendering ?

That HL is still single core only and so quite slow.

Maybe it is much faster if you use OpenGL without Color and activate lines there,

if applicable for you, or any other mode.


Another Option would be to render your Viewports over night or use VW Cloud Service to render for you.

Link to comment

Yes, I meant hidden line. Thank you for the correction

The problem with open gl is that it turns the linework into an image, which can be illegible once printed on a larger scale format. Everything has to be a line drawing, especially for sectional drawings. 

I'm worried how it will behave when i create full building sections when all elements will need to be rendered. Of course the section line depth will save me to a degree, but still very frustrating. Wondering how it can be improved in any way?

Edited by Samuel Derenboim
Link to comment

OK, so you rely on HL Renderings.


All you can do to accelerate this is to have enough RAM to not need to swap to disk

(Watch task manager but I think 16 GB should be sufficient)

And get the fastest CPU that has the highes frequency in in single thread Turbo Mode

(As all other cores will sleep anyway. Don't know if overclocking will change much in Turbo Mode ?)

Distribute Viewport Renderings to different machines to render one VP per machine.

Or parts of it in the Cloud or over night or from time to time update one VP while working*.


* I thought it is possible to go on working while VW renders VP'S ???

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...