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white corrugated metal / lighting balance

Posted by jeff bergeron on June 15, 2016 at 11:42am in IRender nXt ArielVision 3D Design Studio (Sket

hi all... few issues... as it's been awhile sense i've been in the rendering environment and getting frustrated with lighting controls in iRender nXt for sketchup.  i have posted an image of a preliminary rendering.  the house is cladded in all white corrugated metal, as you will see the roof (as well as some of the walls) are blown out and i can't find any suitable light balance to show the corrugation correctly while still exemplifying that this building is white. also, very frustrated with the reflections on the doors/windows that the software is adding.  any help would be much appreciated.  as i'm test running this software and would rather see what it is capable of without bringing images and layers into photoshop.

thanks in advance.

j

lot4sq.jpg

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Replies

  • Russell D. Houlden June 16, 2016 at 9:50am

    This rendering is being processed with the IRender nXt unbiased rendering engine (Path Tracer).  The only other difference is that I also turned on the sun, then lowered the sun intensity to soften the sun shadow.  Because the Path Tracer solves lighting with no "bias" - the bounced light is very apparent, look at how nice and white the walls are!  The sun is also illuminating the interior, so the reflections in the glass are more subtle.

    Always a good idea to become familiar with the three options for rendering:  Packet Mode - biased; Path Tracer - unbiased; and our Hybrid - Engine 4.  Once you're familiar it will become easy to decide which engine to use for the scene you're rendering.

    2506663465?profile=RESIZE_1024x1024

  • jeff bergeron June 16, 2016 at 7:00am

    russell... thank you very much for your assistance.  very helpful. 

    regards,

    jeff

  • Russell D. Houlden June 16, 2016 at 5:13am

    We're always eager to help people learn about our software.  Rendering is a complicated topic and we work very hard to make sure that our software is the easiest to learn and use.  Having said that, there are always a few things that are somewhat subtle and so more deserving of an explanation.  I hope that you will not hesitate to continue to post questions to the forum, these are topics that are interesting to everyone.

    Russell D. Houlden said:

    Jeff:

    I sent you a private email with your model.  Let me know if you don't get it in the next few minutes and I'll try again.

    jeff bergeron said:

    russell,

    thank you very much for your help on this...

    where is the link to the modified model? 

    thanks again!

    j

  • Russell D. Houlden June 16, 2016 at 5:03am

    Jeff:

    I sent you a private email with your model.  Let me know if you don't get it in the next few minutes and I'll try again.

    jeff bergeron said:

    russell,

    thank you very much for your help on this...

    where is the link to the modified model? 

    thanks again!

    j

  • jeff bergeron June 16, 2016 at 4:53am

    russell,

    thank you very much for your help on this...

    where is the link to the modified model? 

    thanks again!

    j

  • Russell D. Houlden June 16, 2016 at 4:49am

    Here's the model:  lot4_modified.skp (.zip)

    Russell D. Houlden said:

    The HDRi is a 360 degree image around the model.  It's high resolution and so works well with a high resolution rendering.  Yes - that's why the trees are reflecting in the glass, because this HDRi is surrounding the model.

    jeff bergeron said:

    rich,

    this is definitely going in the right direction. few things on reflections in this software.  you mentioned you used a hi res image... i'm assuming that this is the (tree) image in the background?  is this how windows reflect?  from the background image?  this is going to be a tricky image to get just right... as in this case the corrugated metal (both on roof and walls) are 'white' corrugated metal.  but i'm liking the way this gray is translating this.  i'm excited to see this thing render as a whole.  anyway you could send me back my file so i can see the settings that you changed... or take screen shots?  i really appreciate your help on this.   

    j

  • Russell D. Houlden June 16, 2016 at 4:40am

    The HDRi is a 360 degree image around the model.  It's high resolution and so works well with a high resolution rendering.  Yes - that's why the trees are reflecting in the glass, because this HDRi is surrounding the model.

    jeff bergeron said:

    rich,

    this is definitely going in the right direction. few things on reflections in this software.  you mentioned you used a hi res image... i'm assuming that this is the (tree) image in the background?  is this how windows reflect?  from the background image?  this is going to be a tricky image to get just right... as in this case the corrugated metal (both on roof and walls) are 'white' corrugated metal.  but i'm liking the way this gray is translating this.  i'm excited to see this thing render as a whole.  anyway you could send me back my file so i can see the settings that you changed... or take screen shots?  i really appreciate your help on this.   

    j

  • Russell D. Houlden June 16, 2016 at 4:25am

    Jeff:

    Our software does not discriminate and works exactly the same for SketchUp Make and Pro.

  • Russell D. Houlden June 16, 2016 at 4:22am

    While this rendering is processing - (at around pass 130) I opened the "Adjustments and Filters" and "Light Balancer" dialogs.  Even though these are typically considered to be post-processing features, they can be used while a rendering is underway.

    I lowered the brightness, increased the contrast, and lowered color saturation.  This was all in an attempt to make the rendering more natural.  The model doesn't have a ground plane (landscaping) so the ground is just the HDRi and obviously the building is not "sitting" on the HDRi very well.

    White (255,255,255) can't get "more white" - it can only get less white based on direct and indirect lighting.  The HDRi does have an affect on the building because there are multiple (natural) sources of light from the image, the brightest of which is the sun.  The shadows are realistic and a bit softer than what the sun would produce were it not obscured by the trees.  It is not difficult to match the HDRi sun position with SketchUp's interface - and then you can balance the intensity of the sun so that it isn't as harsh as it will be if left at full intensity.

    Using Adjustments and Light Balancing while the rendering is processing ensures that the completed rendering will match my expectations because the lighting solution and reflections will only improve with each successive pass. 

    2506663848?profile=RESIZE_1024x1024Very interested to hear your comments and again I hope that this information is answering some of the questions that you have and is helpful to you as you continue to explore the features of IRender nXt.

  • jeff bergeron June 16, 2016 at 4:10am

    ohhh... btw... i am using a free version of sketchup (make).  does that make any difference with this software?

    thanks again!

    j

    Russell D. Houlden said:

    Jeff:

    Here are a few images.  If this is moving in the right direction, that is, more along the lines of what you're hoping to see in the renderings, the changes are not difficult.

    The corrugated roofing was white.  When light, especially sunlight hits this roofing, it's going to get brighter and so the result is that the roofing goes flat.  Of course corrugated metal isn't white, it's gray.  It's also got some ability to reflect.  I made it gray (although I didn't take the time to do an actual color match) - and I set the reflection on the roofing to "plastic" because I think you wouldn't like too much reflection.  The rendering preset I used is HDRI and using a hi-res HDRi image that I have on my computer.

    The images are after just 35 passes.

    White is always tricky because all visible light gets reflected off of white and that can mean that although your mind perceives "white" - there is usually very little actual white on any given surface of a real building.

    Black is interesting too, a computer can represent black very well (0,0,0) and true black doesn't reflect any light.  So black that will reflect (a shiny black car, for example) - actually has to be not perfectly black (10,10,10) to mimic what black typically does in the real world.

    2506664479?profile=original2506672382?profile=originalWere this my model, I would bump up reflection on the metal roof, especially if this is new construction.  The glass is reflecting properly, it's darker behind the glass than in front which will make glass more specular (mirror like).

    I do hope that this is helpful.  This particular rendering does not use the sun but only because the sun angle and shadows are being set by the HDRi.

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