Print at Dec 6, 2019 8:25:57 PM

Posted by Puybaret at Mar 25, 2011 1:29:05 PM
Re: Daylight Room Rendering
Never thought about HDR software to post process computed images ! smile
Even if this sounds as a good idea, I don't think it could work even if you add more light sources outside. It's because light reflections are limited in Sweet Home 3D, otherwise it would take too long to compute an image. I know computed images are therefore less realistic, but it's a tradeoff.

Sometimes, I'm tempted to add an additional higher quality level that would use the capabilities offered by SunFlow Instant GI, but I believe users prefer to add more lights and get faster a nicer image.
For example, the following image of an empty room was rendered in 3h50 (13800 seconds!) with Instant GI on an i7 processor (measured from the value displayed in a top command) :

With the current renderer that uses some ambient occlusion and no additional light the same image was rendered in 31 seconds:

With one large light added at the ceiling of the room, the image is computed in 42 seconds and looks much nicer at the end:

If ever you're a Java programmer, you can test Instant GI quite easily in Sweet Home 3D source code by changing the following lines in the PhotoRenderer class:
- replace the lines from 366 to 374 after the test on useAmbientOcclusion by the following ones:

this.sunflow.parameter("gi.engine", "igi");
this.sunflow.parameter("gi.igi.samples", 256);
this.sunflow.parameter("gi.igi.sets", 1);
this.sunflow.parameter("gi.igi.c", 0.0000005f);
this.sunflow.parameter("gi.igi.bias_samples", 8);

- change the diffuse value at line 301 from 1 to a higher value (this value is the number of bounces):

this.sunflow.parameter("depths.diffuse", 8);

You can try to change "gi.igi.samples" to get better or worse noise, change the number of bounces...
Emmanuel Puybaret, Sweet Home 3D developer