Hey guys, I am trying to use some emission color lights. But an emission intensity less than 1 will not be enough to illuminate surrounding objects, enough intensity will make some low-saturation emission colors overbright and become white… I'm a novice in rendering performance. Can it display accurate colors with high brightness (enough to illuminate the surroundings)? Or this is indeed physically normal
it's pretty common and indeed normal, it would be alarming if it didn't go towards white with bright emission as that would mean that one of your channels is probably 0
however to compress your range of the final image and bring owerbright areas back to the visible range it all comes down to what LUT you are using or alternatively to your comp
tamte however to compress your range of the final image and bring owerbright areas back to the visible range it all comes down to what LUT you are using or alternatively to your comp
Sorry, I just started to know the concept of LUT. Does this mean that the image I currently see in the render view is not the correct color if I don't use LUT? And if I have multiple emission lights with different colors, do I need to create and debug LUTs for them separately, or for each different rendering view, or only one LUT can be applied to the entire hip model? Will LUTs affect other parts of the screen after back to the visible range? And is it a common and correct way to illuminate the scene with high-intensity emission color geometry? Sorry for too many questions
Going back to your original question, I think you are wondering how to render an emissive object that is bright enough to illuminate nearby objects but is itself not so much affected by its own emission that it appears white.
You could consider turning your emissive geometry into a geometry light (https://www.sidefx.com/docs/houdini/shelf/geolight.html). That way you can crank up the intensity of your geo light as much as you want, and you can exclude the original geometry from being illuminated by the geo light (e.g. by setting its light mask). This won't be physically correct but it may give you the look you are after.
If the light source is saturated enough, it won't clip to white depending on the viewing lut. Photographs of some neon signs and other spectral sources often don't clip white. The device transform can make such saturated sources look solarized though. Any less saturated source will tend to white as it overexposes, just like a photograph.
Elonw Sorry I'm a bit confused, do you have time to elaborate on this process
You can render the contribution of each light as its own AOV so that it appears as a channel in your exr file. You can see these channels also in mplay by choosing something other than “C” in the dropdown, (fourth widget from left in mplay).
To do this:
In the VEX variable entry, choose “Direct Light Per Component” Enable “Export Variable For Each Component”
