The advanced rendering settings have one of the most important parameters, which is responsible for reflexes and reflected light from the surfaces of objects. Pathtracing. It is impossible to get a realistic picture without it. This parameter is very energy-intensive and very difficult to work with in SH3D. And it is necessary. What can be done? Sjb007 gave a hint that it is possible to make ONE dominant light source and not make other sources that are usually made in the interior. This dominant main source is the street light that penetrates through the window into the room. Most rooms have windows, fortunately)). I created a complex 3D room scene in the SH3D program. Landscape outside the window I have this image of the city on the front of a large box, the box is installed near the window. To make such a landscape look plausible, you need to set the horizon of the picture correctly. Now I need to make the dominant light, I installed an invisible light panel, rotated it 90 degrees, set it 10 cm in front of the landscape box and directed the light into the window column. It's just like in reality. The lower edge of the panel should be positioned at the horizon level so that the main rays illuminate the surfaces on the floor, and only a small part of the rays fall on the ceiling, as in reality in daylight with diffused light from the street. The light mostly goes towards the floor, not towards the ceiling. The panel power is 10%, the color is white, you can use a little blue. There are built-in lights on the ceiling, I have placed mini-spots from the library, the power is 30%. These mini spots are also inserted wherever there are light sources - in chandeliers and sconces. Now you need to set the rendering parameters. Immediately set the highest quality level to 4, although it will still be terrible quality.
The DiffusedBounces parameter is responsible for the intensity of reflected light from surfaces. The larger it is, the stronger the effect of the color of objects on the color of the render as a result. For example, if there are a lot of green objects in the room, then at a maximum value of 9, the render will be mostly unnaturally green from reflected light. Therefore, you do not need to bet a lot. 3-4 are enough. All other parameters can be left unchanged, as they are in the basic setting for quality level 4. There is also an additional option, Enable Sky Lighting, it seemed to me that with this option enabled, the rendering speed slightly improved, but this is not accurate. The mode itself does not affect anything in the picture, because the whole landscape is an image on the box, there is no sky here.
My 3D room scene took 4 hours to load at a quality of 4 and a size of 1000 pixels (I took a square). Look at the terrible noise and all the wandering dots. Nightmare. But it's almost a victory!! Without suffering, we got a very realistic picture of the interior with daylight diffused. There are no hemispheres, spheres, or additional panels. There is only one panel on the street and formal minispots for marking point sources. But there are no black unnatural surfaces at all, which are already boring. Everywhere there are truthful surfaces illuminated by reflected light. Realistic image!! It's okay that it's terrible and noisy. This is fixable.
Yes, I forgot to say that you first need to make a few trial runs at 200 pixels to adjust the brightness level. And only then do a terrible noisy render of 1000 pixels.
Well, now the main secret. You need to make a render with a quality of 1 (where light is not taken into account) with a size of 4000 pixels. This will be the benchmark for picture clarity. And the lighting reference will be a terrible render with noise and white dots. And now everything needs to be uploaded to AI. It is useful to add pictures of a glass chandelier to clarify, write a promt, where everything is explained once again. But the samples and standards are starting to work!!! And almost on the first attempt, a high-quality render is obtained. This method does not require the skills of an artist, it is automatic. And the most important thing is maximum control over this uncontrollable AI. Although of course there are still no guarantees. I hope Sjb007 and SM will be able to embed DD3D inside SH, and then these tambourine dances won't be needed..
And the gradient and stripes are the features of photo hosting. They seem to compress a large image with such defects. I have everything exactly right in the source file.