New Build (291)

[Roy Hirshkowitz]

This one introduces two new engines.  Both of these are very experimental at the moment. I may not retain either of them if they don't prove useful.  Although they appear very stable, there may be some hidden bugs.  Be careful using these for production until we have some confidence in their stability and characteristics.  The engines are only accessible via the nXtEngine AutoLisp command use (nXtEngine 2) -OR- (nXtEngine 3).

Both engines include more light pathways than the current product does and can therefore potentially provide more accurate solutions.  Two "tricks" which are used in the first two engines, transparent shadow rays and daylight portals, are not used in these new engines.  This gets rid of two big sources of inaccuracy.  Caustics pathways are automatically included.

Engine 2 can be much less noisy than the Path Tracer for most interiors.  It's convergence, on the other hand,  is not as graceful and will include some discrete artifacts.  It's usually a lot faster than the Path Tracer for interiors.

Engine 3 is a little more accurate than Engine 2, particularly when window coverings are involved.  It converges more gracefully, but slower for some interiors.  It is considerably faster on some exteriors.

Some things to keep in mind with these engines:

• Light leaks in the corners are possible when doing interiors.  Make sure walls, floors and ceilings are modeled as slabs with thickness.
• Both engines start slowly and accelerate.  Pixels/sec should increase as they proceed.
• Using accurate IORs is very important.  IORs of 1.00 should not be used for glass.
• Designating glass as Thick/Thin is more important with these engines.
• Translucency is not implemented.  Allow Surface Roughness is.
• These engines use more memory than the previous two.  64 bit is recommended.  Start your testing and low resolutions.

Let me know what you think-- I'm looking for feedback here.

[Roy Hirshkowitz]

Try it again now.

[Rey F. Rosario Berrios]

Now it's ok. Thannk's Roy!!!!

[akinlolu olugboji]

I can minimize both rendering and walkabout window in both engines. 

[Miguel Tano Adanes]

Am I missing some components of ACAD? nxtengine command does not exist... How to go back to engines 0 or 1?

[banjoko]

 i downloaded new build 292,but the command line is showing  Unknown command "NXTENGINE3".  Press F1 for help, is it bcos am using trial version and 32 bit?

[banjoko]

got it 

[Alejandro Testa]

Hi Roy, I am loading a model  (80 MB)  when I tried to use (nxtengine 2) autocad  nxt crashed,  I open the walkabout window, press the render button, the model start to load when it finish and  preparing render  window appear it crash.  I tried at least four times and always the same. I can load this model with (nxtengine 3)

I  tried with another model (no so heavy) 29 MB, and the image start rendering.

I have one question about rendering quality, Is normal with both engines at the beginning to have big spots on the image?  (see attached)

[Miguel Tano Adanes]

The same here. When nxt finishes loading the model, Acad shuts down.

[Roy Hirshkowitz]

32 or 64 bit?

[Miguel Tano Adanes]

64 bit. See my further comment. Engine 2 crashes, engine 3 works.

[akinlolu olugboji]

64 bit here and no crash on both engine.

[akinlolu olugboji]

Not as much spots, noise only on shiny materials.