Chaos Corona Forum
Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: Torsten on 2015-08-28, 10:28:34
-
Hey guys,
I need some help setting up nice lighting for a studio setup. The problem i am having is that the lighting isn't creating nice soft shadows, the shadows are to pronounced. I attached the clayrenders, light setup and a screenshot of the scene. I have created a nice soft backdrop plane. I lit the scene using 3 fairly large Arealights. The lighting is composed of two coloured key Arealights, 1x1 m and 2x2 m, Lefty and Right. An additional fill light is placed above the scene, this one is 2x2 m. I vave also loaded a grey color in the environment slot, making the total scene a bit brighter.
In vray I used to use softboxes for arealights, making the shadows a lot smoother . How do i need to set this kind of lighting in Corona. Do i need to make the arealights bigger in dimensions? I would like to keep the sizes of these arealights as close to reality as possible. The dimensions i used in this setup are already a bit too large.
EDIT: I am aware that there are good hdri's available for studio setups, but i really want to be able to control the color and the lighting myself.
Thanks for the help!
-
Hi, the result is physically correct so you will need to alter something in order to change appearance of shadows. This should look 99% same in any other renderer which supports area lights. Bigger lights = more blurry shadows. One not so obvious solution might be to increase the brightness of materials (especially the background) - this will reduce overall contrast of GI. You can also try changing light shape to disk, or using a gradient map as their texture.
-
Another trick would be to put a thin object in front of the lights. Like a sheet. Like a real-life diffuser. But this would probably make your rendertimes crazy.
-
Another trick would be to put a thin object in front of the lights. Like a sheet. Like a real-life diffuser. But this would probably make your rendertimes crazy.
This would be absolutely pointless. Corona lights are already perfectly diffuse unlike their RL counterparts.
-
Thanks for the help.
How can I put a texture for arealights Maru? Or would you then use a CoronaLightMTL on a plane geometry? I already thought about using a CoronaAO to recreate softbox like lighting.
If i would use a plane with coronaLightMTL, would this deliver the same lighting result as a Corona Arealight? And would this also render as efficiënt as an Arealight?
-
How can I put a texture for arealights Maru?
You have a "texmap" slot in CoronaLight.
I already thought about using a CoronaAO to recreate softbox like lighting.
DON'T.
If i would use a plane with coronaLightMTL, would this deliver the same lighting result as a Corona Arealight? And would this also render as efficiënt as an Arealight?
There should be no difference.
-
I tried using disk coronalights, but there is not that much of a difference, still strong shadows. I also gave the gradients a try as a texmap for CoronaLightMtl. This also did not give me the desired result. I attached an image that i rendered using an HDR as light source. This HDR had Softbox like lightsources, giving a really nice smooth shadow. I want to try and recreate this lighting, but than with coronalights, this way i have more control in the overall lighting.
-
As you probably already know, shadow softness depends on light source size and distance to object. Light source shape doesn't have much impact here. If you render same scene with Corona and Vray or any other physically based renderer it should provide exactly the same shadow softness. If not, then clearly somwhere is a mistake.
-
Yes i know. The above image lit with an HDR is also Corona rendered (previous reply). This is the shadow smoothness i want to achieve. The HDR i used i got from a tutorial, and was made with HDR Studio. I has very nice soft lightspots, which results in the soft shadows. I would like to recreate this with corona lights and keep it as realistic to an actual photostudio as possible. That's why i tried to use the gradients Maru explained, but i didn't get this to work.
This is what i have got so far (attachment). It has fairly large arealights, 2x2 meters, no gradients applied, just coronalights. I am already pretty satisfied with the result, although the shadows are a bit too pronounced.
-
perhaps you have some examples of existing softboxes you like in terms of soft shadows you could put up to help everyone refer to.
-
Gradient won't help. In fact it only can make your shadows appear more harsh, because it effectively reduces area of light source. Gradients good for reflections though.
Don't be affraid to make your softboxes larger or move them closer to subject. In real world there's so much more light contributing to lighting, but in CG most of the times there's absolute darkness behind a scene and not enough walls for light to bounce.
BTW, did you know that gradient ramp has different gradient types, like box or radial. There's no need to combine 5 maps when you can do same thing with only one ;]
-
Maybe you could try using a box around your whole scene. The bouncing light might help to soften your shadows too.
In real life there is always a room around your scene ;)
Greetz
Lucutus
-
Maybe you could try using a box around your whole scene. The bouncing light might help to soften your shadows too.
In real life there is always a room around your scene ;)
Pretty much* the same as adding a HDRI or solid bg color.
*I added that not to be insta flamed ;)
-
@maru
of course its similar to the use of an HDRI, this would have been my first suggestion.
Maybe i got it wrong but as i understood the question, tmiddelkoop wanted to avoid the use of an HDRI.
greetz
Lucutus
-
Yes,
I have added a solid color (40 grey) to the environment, this helps the softening a bit. I also followed Romullus' tip and enlarged the area lights to 3x3 en 2x2 meter and reduced the strenght (before 2x2 and 1x1 meter). It helps a bit, but not that much.
But maybe i should increase them to extreme sizes. As i said before, i wanted to stay to real world scale lighting, but cheating a bit to get the desired result is always an option ;-)
Thanks for all your input!
PS i have added the render i made in the beginning, this one is only lit by an hdri, which i attached also. As you can see the bright spots on the hdri are very soft, this results in very smooth shadows in the render. This is the kind of softness i want to achieve, but than with the means of Coronalights instead of hdri, so i have more control over color and amount of lighting.
-
I think those lights in HDRI are much bigger than CoronaLights in your studio. You can see it yourself, create new camera in scene center, apply CoronaCamMod and set projection mode to spherical, set image aspect ratio to 2, hide all geometry, but leave lights. Now render image and compare it to your HDRI. I'm pretty sure that rendered lights will be much smaller. You can even save render to exr, load it to enviroment and render your studio - shadows should remain exactly the same as with CoronaLights.