Raytrace help


Stevenplane
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Attached is the file of a bathroom I'm helping a friend to remodel. 

I thought it would be an easy raytrace but I let this run all afternoon and after 68 passes, the attached pic is what it looked like.

Any help with the raytrace settings would be much appreciated as I've never really spent any time doing them.

Side note:  I have a Surface Book with an NVidia GeForce graphics card so it should easily handle this.

Thanking everyone in advance,

Steve

Melton_bathroom.zip

Bathroom Raytrace.jpg

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Ray Tracing is really in art form in my opinion that takes butt-loads of time to master.  I could spend all day writing up some of my own personal recommendations...but here are a few of the quick tips I would offer right off the top...

 

  • Make sure you really need the Ray Trace as PBR may suffice.  Ray tracing is more time consuming and although its results can be far more realistic and its capabilities far more robust, its also quite a bit more complex and has a larger learning curve in my experience.
  • When playing around with settings, don't render the whole screen.  Under Ray Trace Options, set the size to a small sample area just so you get a  feel for what it's going to look like.  If its obvious it's going to look bad than you're only out several seconds or maybe a few minutes rather than many minutes or even hours.
  • Don't expect more passes to fix glaring issues.  In general, you should see a pretty close example of what it's going to look like be about the 4th pass and 16 passes is typically about as good as its going to get.  It will continue to clarify and improve in minute amounts, but IMO, anything beyond about 4 will just be for clarity and anything beyond about 16 will be inconsequential for almost all standard uses.
  • Turn off lights that aren't affecting your scene.  This accounts for more extra processing time than anything else (except maybe the image size).
  • Lighting and Material Definitions are key.  This subject alone could take all day and I don't really have time to get into it, but maybe someone else will chine in with some pointers.
  • Don't undervalue post processing.  Sometimes a dark scene can be all but completely fixed by simply using the Adjust Image Properties tool or by editing in an outside photo editor. 
  • Remember that a good, realistic render starts with the model itself.  Sometimes the difference between a great scene and a mediocre disappointment has nothing to do with the rendering quality and everything to do with the time and detail put into the model itself and how its set up.  Take time to add the realistic elements and little details, and decorate the room as necessary.  Throwing a cabinet and a tub in a  bathroom will look like crap even if you took an actual professional grade photo and tried to pass it off as a ray trace.  Same bathroom with an appropriately selected high quality tub symbol, detailed tile work, moldings, a well thought out vanity cabinet, light fixtures, outlets, switches, bath hardware, etc. will make all the difference.  Add some time creating cabinets, countertops, and moldings with slightly eased edges (a tip I gleaned from @Renerabbitt a while back...thanks buddy :)), etc. etc. and you go from mediocre to pretty good.  Next step, master that lighting and those material definitions and you just might move into great.

 

P.S.  Your video card doesn't do anything with Ray Tracing.  That's all done with your main CPU. 

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Lots of good Info above  you'll also find two threads here on the Forum , one called Lets' Raytrace and another called Lets PBR , ( short for Physically Based Rendering) both have a lot of good info, if you are willing to put in some time and  "practice" some ..........unfortunately both come with a bit of a learning Curve , there is no set it and forget it button.

 

A lot of people have switched to PBR these days due to the Speed ....10-60 secs.....rather than hours in some cases.... and most people are happy with it..... 

 

The biggest Issues in your Plan are :

1.) the fact you only built the Bathroom , so CA is having trouble lighting the scene properly , I always recommend you build a "box" house around the Reno and then add a Auto foundation under it and a roof ( or another floor) above it , to help CA's Lighting engine do it's job properly , this will help with the weird "Glow" at the Ceiling and other places in the Image above.

2.) The Ceiling , Walls etc etc are ALL the Porcelain Material which is reflective so likely to be an issue in Raytrace as there is just too much of it  ....

3.) you need to add a few more recessed cans to help with the lighting, and some Windows in the "Bedroom" ( see box house note above) behind the bathroom for the "sun" to shine in...

4.) as Michael suggested adding a few "details" can make all the difference to a render whether in Raytrace or .....

 

 PBR ..............

 

Melton Reno.png

image.thumb.png.05f657e46f74ba6af82c1d26eded371e.png

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13 hours ago, Alaskan_Son said:

Ray Tracing is really in art form in my opinion that takes butt-loads of time to master.  I could spend all day writing up some of my own personal recommendations...but here are a few of the quick tips I would offer right off the top...

 

  • Make sure you really need the Ray Trace as PBR may suffice.  Ray tracing is more time consuming and although its results can be far more realistic and its capabilities far more robust, its also quite a bit more complex and has a larger learning curve in my experience.
  • When playing around with settings, don't render the whole screen.  Under Ray Trace Options, set the size to a small sample area just so you get a  feel for what it's going to look like.  If its obvious it's going to look bad than you're only out several seconds or maybe a few minutes rather than many minutes or even hours.
  • Don't expect more passes to fix glaring issues.  In general, you should see a pretty close example of what it's going to look like be about the 4th pass and 16 passes is typically about as good as its going to get.  It will continue to clarify and improve in minute amounts, but IMO, anything beyond about 4 will just be for clarity and anything beyond about 16 will be inconsequential for almost all standard uses.
  • Turn off lights that aren't affecting your scene.  This accounts for more extra processing time than anything else (except maybe the image size).
  • Lighting and Material Definitions are key.  This subject alone could take all day and I don't really have time to get into it, but maybe someone else will chine in with some pointers.
  • Don't undervalue post processing.  Sometimes a dark scene can be all but completely fixed by simply using the Adjust Image Properties tool or by editing in an outside photo editor. 
  • Remember that a good, realistic render starts with the model itself.  Sometimes the difference between a great scene and a mediocre disappointment has nothing to do with the rendering quality and everything to do with the time and detail put into the model itself and how its set up.  Take time to add the realistic elements and little details, and decorate the room as necessary.  Throwing a cabinet and a tub in a  bathroom will look like crap even if you took an actual professional grade photo and tried to pass it off as a ray trace.  Same bathroom with an appropriately selected high quality tub symbol, detailed tile work, moldings, a well thought out vanity cabinet, light fixtures, outlets, switches, bath hardware, etc. will make all the difference.  Add some time creating cabinets, countertops, and moldings with slightly eased edges (a tip I gleaned from @Renerabbitt a while back...thanks buddy :)), etc. etc. and you go from mediocre to pretty good.  Next step, master that lighting and those material definitions and you just might move into great.

 

P.S.  Your video card doesn't do anything with Ray Tracing.  That's all done with your main CPU. 

 

Excellent advice.

 

The only thing I would add is that I never go beyond 10 passes. 

 

Ray Tracing can be an eternal hell but ultimately yield beautiful results, and it takes many hours of trial and error for the tool to become even remotely usable.

 

14 hours ago, Stevenplane said:

I've never really spent any time doing them.

 

Yep, it is NOT a "push button, get results" tool.

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