Games' speed vs Revit Speed

[dwills.114624]

From a programming point of view Revit's display performance on compatible hardware is remarkable given the job it has to do. I have compared Revit's speed with its leading competitor and let's just say there is no contest. Spinning a building model in hidden line or shaded mode without the whole model disappearing (I know it does on some hardware) takes some programming effort. As a comparison, export your Revit model to AutoCAD and open it, turn on the conceptual visual style and try the same spin. AutoCAD will throw a rod...

Now, the other reason why games are light on their feet is not just low polygon count, which isn't always that low anyway, it is the precision at which the faces are calculated. Revit is *cough* a CAD program *cough* and as such requires far higher display precision than the average game. Also, games scenes are "pre-rendered", adding vastly to the realism without sacrificing performance on a modern video card.

The application I would like to see is an exporter that exports the Revit model via FBX/DXF or similar to a walkthrough application based on one of the GPL licenced game engines, such as Quake 3 (more than enough power -- http://www.idsoftware.com/business/techdownloads/). THAT would be the killer app. Best of all, as it would be GPL, it would be free...

DW

[mthurnauer]

There is also another aspect of it which has to do with hardware designed specifically for one type of task verses being flexible to handle any task. If you were to build a machine with a processor designed specifically for Revit and a graphics card specifically for revit and then an operating system that was nothing but a portal to facilitate the function of revit, you would get much faster performance. Then there is another thing that also enhances the performance of gaming systems which is available in other 3d applications such as 3Ds; you can tell the program what objects cast shadows and which do not. You can also limit what surfaces receive shadows. Along with this is the ability to indicate which lights cast shadows and indicate that the lights only cast shadows for certain objects. So, you can have one light that creates the shadows for the animated characters and the lights that make the scene look realistic may not be calculating shadows for the moving objects. Some of the environment lights may actually have their light and shadow baked into the materials.

[Tom Phillips]

A little off subject, but...

Has anyone performed a side-by-side comparison with 2010 32 bit vs. 64 bit, using the recommended hardware setup?

[ron.sanpedro]

A little off subject, but...

Has anyone performed a side-by-side comparison with 2010 32 bit vs. 64 bit, using the recommended hardware setup?

In general my sense has been that there is rather little speed difference between the two, but a HUGE stability difference. There will be a small band of model sizes right below the threshold of what Revit x32 can handle where 32 bit will start to page and 64 bit won't, and thus x64 will be faster. But in the majority of cases x64 just means your model can be bigger. in x32 that model will simply crash Revit, and in x64 it won't. Of course x64 is more useful if in fact you have more RAM, so a comparison of both at 4GB is going to look a lot like parity, with x64 seeing a little benefit due to how memory is managed (meaning more of that 4GB will actually be available.) x64 really doesn't shine until you have more RAM than x32 could use, so apples to apples hardware is a meaningless comparison.

And for what it is worth, when going to 64 bit, I can't recommend anything other than Windows 7. XP x32 is viable, but XP x64 is a joke. And Vista is fustercluck of epic proportions. Windows 7 solves a good chunk of Vista's garbage, adds some very useful features compared to XP, and offers real benefits with regards to powerful graphics cards and such. There are very real issues (printer drivers, VOIP Outlook integration, etc), but if you need 64 bit Revit, the strengths of Win7 far outweigh the weaknesses.

Gordon

[ben.136902]

Lot of misinformation on this thread. Modern games have extremely high polygon counts, much higher than that of revit users typical models. The graphics engine is written much efficiently to use the video card to help with this additional load. Revit only uses cpu power, the video card is maybe 5% of the total when it comes to revit performance. Faster the cpu the faster revit operates.

Also major other programs were written to be fully multi threaded that use vastly more complex processing engines and much higher floating point calculations in far less time than its taking autodesk. Is that because the developers at autodesk are not good, i doubt it...i doubt it was much of a priority.

Again modern games are much more detailed than any revit model in terms of the # of polygons processed and the # per second or frame rate. Take a look at a modern world of any advanced PC game i.e. cyprus and there is no comparison. Hence why dual video cards are often required to maintain the frame rates and why changing the CPU speed after a given medium to high rate only affects certain game benchmarks. All the processing is offloaded to the GPU that can process many threads at once whereas revit is still based on technology that was built in the late 90's.

[webmaster.84284]

One huge aspect that's been missed here is how the geometry works in games vs revit.

I think you'd actually be surprised at the level the meshes in games these days. Still, it's not as complex as a standard 3D model.

The big difference though isn't as much complexity but the aspect that makes things like revit what they are, that being, their parametric abilities. If you think of a wall as a 6 sided object, it has just that - 6 sides - and 8 vertex points defining it's corners. A game model has to remember just that. The location of the 8 vertex points and the associated faces of that piece of the model. In Revit, it has to remember that, plus the definition of the wall. It has to be able to display that wall in 2D or 3D views at the drop of a hat. It has to retain everything that makes it a wall. The ability to add a door or window to it and then all the properties of that door. And all the basic wall properties as well....You can keep exanding the list of everything revit has to track for a basic wall in a scene when you rotate it or change views, etc.

In a game, you have a bunch of static objects that don't actually do anything but exist. They have no ability for special funcitonality. Those objects in a game that actually have special funcitonality are reserved just for those things. A wall that explodes into 50 piece has more properties, but the other 500 walls in the level don't have the properies. General meaning being a building with 500 walls has over 100x more information in it with revit than the same building will as a game level.

[cliff collins]

webmaster raised a critical difference in games vs revit.

An analogy could be made between revit and 3dsmax or Sketchup.

BIM modeling and purpose is TOTALLY different than a "throw-away"
visualization model made out of "paper thin" meshes and polygons like in 3dsmax
or Sketchup.

You could build the same project in revit and in 3dsmax, and then total the number
of polygons and revit's would be far greater.

The BIM software is keeping track of intelligent relationships between model elements, schedules, sheets, views, etc. where a "viz" model is just faces with maps applied
for rendering and animation.

It is not a valid comparison to even try to "benchmark" revit against a game-engine model.
2 completely different "worlds" --pun intended.

As a side-bar to this thread, there are a lot of designers who want to take their revit models
and place them inside a gaming engine like Crytek and Unreal--to get the best of both "worlds", so to speak.

cheers

[rudolfesterhuyse]

Thanks for all the info...it is really insightful. I've always suspected some programming inefficiencies in Revit but this has given me some new food for thought.

As a side note: How easy is it for Revit to recruit and retain the best programmers compared with say gaming companies? If you are a programmer would you rather work forAutodesk on Revit or for a gaming company or does if not really matter much in terms of what you do, what you get paid etc.?

[Captainkb]

Thanks for all the info...it is really insightful. I've always suspected some programming inefficiencies in Revit but this has given me some new food for thought.

As a side note: How easy is it for Revit to recruit and retain the best programmers compared with say gaming companies? If you are a programmer would you rather work forAutodesk on Revit or for a gaming company or does if not really matter much in terms of what you do, what you get paid etc.?

Here is a test that I did. Bring in a Revit model into a game engine (Unity3d), and see what I can do. I didn't get to geeked up on materials, when I exported the model to .FBX the lights were shut off. I imported 2 videos also pretty easy to do.

Exported Revit straight to .FBX. Unity3d imports .FBX pretty easily. I guess some people have told me that it is real jerky on there pc. I did try it on my home laptop with a wifi and it was jerky...lol Can anybody tell me if it runs smooth on their pc?

http://www.kb3dgraphics.webs.com/

[Paul Monsef]

Can anybody tell me if it runs smooth on their pc?
http://www.kb3dgraphics.webs.com/

Hey that's pretty slick. It ran smooth here.