Good morning everyone.
a few days ago I started experimenting with the use of Keyshot 2023.
I’ve seen some video tutorials (KeyShot Essential) and I want to better understand how the “environments” and “lighting” features work.
for example: I have seen that a “cube” type object placed inside the “sphere” environment, if it is moved out of the center of the scene, projects a sharp shadow as if it were near two walls at right angles. why ?
again: how do I understand the lighting system of the “light Tent - Studio028” environment, what are those gray areas within this environment?
grazie a tutti !
I think the best way (at least it was for me) to understand the environments is to open a cube in Keyshot, then load the solid black environment (no lights). Add one light pin, then start moving it around. Black is no light, white is light, grey is a dimmer light.
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The HDRI environments are basically big dome shapes over your entire scene. The ‘size’ under the settings button gives the dome a certain size which will impact the shadows on the scene.
So if the size is pretty small moving a cube out of the centre will make a bigger impact than when you have a large dome. I always try to keep it a bit realistic depending if you do a studio shot or outdoor shot. And I adjust the ‘Ground size’ in proportion
Basically you could create a model of a dome and map the HDRI in it so you know where lights will be. That’s basically like you pick ‘Lighting Environment’ as background (which shows the HDRI) but in a way that can give you a better ‘feel’ of where lights are since you have it actually projected on a dome.
I do the same as Harry, although I suggested a feature that would auto-rotate the HDRI so the brightest spot is pointing at the front of the object. That way you have some kind of guidance since every HDRI is different on what location/degree it’s brightest.
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As with most things, @will.gibbons has a great video on how environments/HDRIs work in Keyshot.
KeyShot HDRI Editor Tutorial for Beginners - YouTube
If you’re ever struggling with something in Keyshot, odds are that Will has a tutorial that explains how to do that specific thing.
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Aside from understanding how environments work from a technical aspect, understanding how lighting works in real life will help you understand why light and shadows has certain properties - as Keyshot does a pretty good job of replicating real life and how light interacts with physical objects.
In regards to your example about the cube and moving it off center causes a sharp shadow, is because either your object is rather large in comparison to your HDRI environment or your Environment is very small in comparison to your object. Softness of light and sharpness of shadow is directly related to the size of your light source vs your object. You will get harder light and sharper shadows if you are using a small light source to light your object. Think a small flashlight placed next to the cube. To create softer light and shadows, you must increase the size of your light source in comparison to your object. A good example is a huge 50-inch lighting softbox next to a tiny screw or other small table top object.
In regards to your question about the light tent-studio028 - the grey areas are the light fall off of the HDRI where the distance is further away from the light source. This creates a realistic fall off of light on your mesh. A lot of the times, people in Keyshot will often use a color overlay or a backplate image for the background over using the actual HDRI. If you are rendering transparent alpha, the HDRI won’t be visible so you don’t have to even worry about the background in those situations in most scenarios. The exception is when you are rendering out transparent materials where the HDRI will always affect the inside of the transparent objects and what is seen in the background of these models.
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Really thank you to Harry, Oscar, Joakim and Oliver.
Very clear explanations, I re-start from here.
