easy rendering for Rhino in Windows
Default render: we obtaint a usable and presentable rendered made more quickly, but he seems to have problems :
I also noticed that some things escaped him at the angle of the object as the passenger side front window or back window driver side .... Sunlight seems to cause problems because of the artifacts appear white on the image .... The reflection of the sky is good but beware of the first pass: it may suggest that you have too much reflection as they will reduce thereafter to disappear .... As against the grain of the paint n 'appears not in the picture, giving it a made too smooth, "too clean ".... and shadows are too hard
Render path: If at first it seems slower, it is not necessarily the reality: in fact if the material is simple, it is certainly slower, but if the material is complex, so it's actually faster and produces a more realistic that the default rendering. but it tends to be worse on the glare as he is better on the grains. also creates dark artifacts (visible on the rearview mirror driver). In the end it produces a more realistic and less smooth than the defaultrender, but that goes more ... he better get by on the angular blend.
I have tests with neutral studio, exterior night, and this...
Interesting experiments. There are many differences between the two rendering engines. I agree with you basically that the default render gives usable results earlier, but the pathtracer can produce more realistic results. Generally, given enough time, the two engine will end up in the same place.
When I work with the rendering engines I notice the big difference in the reflections. The default renderer will always start out with sharp reflections that will blur over time. The pathtracer will start off with blurred reflection right from the start. So, if you see a material in the default tracer that looks good at the start, but gets "worse" overtime, then make the material a little more sharp.
In the rendering you are showing here, I tend to like the 7 min. and 30 min. default tracings for material reflection. That would lead me to increase the sharpness to get a slightly sharper reflection with the pathtracer.
I also think this is a good experiment in time vs quality. When using NXT, at some point the extra passes do not increase the quality of image enough to justify the extra time.
There is a basic difference between the pathtracer and the default renderer. The pathtracer will take lighting calculations from the complete HDRI sphere. The default render will only take lighting from the top half of the hemisphere. I believe this is what you are seeing.
The HDRI has bright beach sand? This brighter areas of the car when using the pathtracer may be from the bright sandy beach. The default render ignores this brightness and in this case makes the lower part of the car darker.
the HDRI is MtMonadnock_1.hdr
after what I see in the material sphere, it is rather the pathtracer (images low) makes a calculation that half of the sphere, as we see the groundplane default (white) when we should see the rocks the hdri. In the Default render (high image), it is all the HDRI sphere is projected onto the material sphere and the car ...
Although the reflections are better made with the default render it produces an image too clean, too render. in short times, there are too many differences between the two types of render to judge the Qualter. and it takes some time to have a fine grain with pathtracer which gives a usable image and the image only 6 hours is sufficient. And the default render it difficult to make short reports with angles on transparent and reflective surfaces and creates errors. and create artefact with sun activated.
I think the biggest flaw is the difference between the sphere of the material in pre-rendering and rendering real-be it in the studio, with or without external hdri. I believe it is necessary to improve the pre-rendering the material
Are you using the normal Sky in lighting, and the MtMonadrack_1.hdr for reflections?
If possible, you can send me the model? Roy and I will take a look. I have setup a similar model, but the exact car you have would be great. You can use this upload link if it is large:
my email is: firstname.lastname@example.org
I have the background image and the HDRI, so you do not need to send those.