Iray shadow control

thorne2

Hello. I hope someone is able to assist me with what I'm trying to achieve, so here goes:

I'm trying to render some game sprites of various props, and I'd like to be able to control the shadows a bit more. I've attached an image of how it looks now vs. what I want it to look (roughly).
On the second image I've just disabled the 'draw ground' option and added a shadow in Photoshop, but I'd really like just to be able to render my sprites and have the shadow looking like that, and not having to go into Photoshop and manually add the shadows for each sprite. 
I've tried several approaches to this, and none has given any good results. Tried sun-sky only, and using an HDRI as light source, but they cast the shadows either too long or too intense. In this render I've set up two spotlights and an emissive sphere. Although the shadows looks nice enough on it, it's unusable because of the fact that there's shadows all over the place, making the image grey where most of it is supposed to be transparent instead.
So my question is, is it possible to achieve a sort of soft shadow like the Photoshopped version of this? And if so, how should I go about doing it?

Thanks in advance!
 

Richard Haseltine

You would need to adjust the lighting to be more directional - Iray doesn't control shadows separately from the lighting.

cgidesign

Must it be Iray, or is 3delight an option for you as well?

I am asking because what you like to achive is something Iray is not made for initially. While Iray tries to mimic real life it cannot "disable" shadows. A workaround would be a shadow catcher, but I tried here on DS 4.16.1.21 beta and the shadow catcher seems to be broken.

But with 3delight it is easy to do what you want because it is a biased renderer that allows breaking "real life" rules.

These are pngs with alpha channel out of 3delight.

 

 

thorne2

Richard Haseltine said:

You would need to adjust the lighting to be more directional - Iray doesn't control shadows separately from the lighting.

By directional you mean that the lights should be more above the figure? 
English isn't my first language, that's why I'm a bit unsure what you mean by it.  

thorne2

cgidesign said:

Must it be Iray, or is 3delight an option for you as well?

I am asking because what you like to achive is something Iray is not made for initially. While Iray tries to mimic real life it cannot "disable" shadows. A workaround would be a shadow catcher, but I tried here on DS 4.16.1.21 beta and the shadow catcher seems to be broken.

But with 3delight it is easy to do what you want because it is a biased renderer that allows breaking "real life" rules.

These are pngs with alpha channel out of 3delight.

 

 

I do prefer Iray, but if it's not possible to do this, I guess I must go 3Delight. 

I did just test it out, but when I set up a scene with lights and all, there are no ground shadows. It's something you have to enable somewhere? I've not used 3Delight in years, so I have no clue about the settings anymore.  

skboa

Can't help with the 3dlight issue, but when you get the shadows working, you could render the object in iray and 3dlight and put the iray version over the object/render with the shadow from 3dlight to get the best of both worlds.

cgidesign

Attached is the 3delight scene - I don't know if you can open it, if I just attach it as a copy from my content folder.

Concept is:

SpotLight shadow -> Light parameters -> Shadow Type is active. Intensity controlls "darknes / opacity".

Plane Ground -> 3delight Material with shadow catcher (done in Shader Mixer) - diffuse color controls color / lightness of shadow

SpotLight fill front, left, right -> Shadow Type none -> fill light without shadow

thorne2

skboa said:

Can't help with the 3dlight issue, but when you get the shadows working, you could render the object in iray and 3dlight and put the iray version over the object/render with the shadow from 3dlight to get the best of both worlds.

That's actually not a bad idea at all!
It will be extra work and because I plan on rendering hundreds of sprites it would take a lot of time. But if it's the only option, I'll have to go with it. 

I did manage to render a sprite that isn't too bad. The shadow is still a bit too dark though. This was made with sun-sky only. If only I could use this and just make the shadows more transparent, it would work. 

thorne2

cgidesign said:

Attached is the 3delight scene - I don't know if you can open it, if I just attach it as a copy from my content folder.

Concept is:

SpotLight shadow -> Light parameters -> Shadow Type is active. Intensity controlls "darknes / opacity".

Plane Ground -> 3delight Material with shadow catcher (done in Shader Mixer) - diffuse color controls color / lightness of shadow

SpotLight fill front, left, right -> Shadow Type none -> fill light without shadow

That's exactly what I was going for. So if all else fails, I can use this for sure. Thanks a lot for this! 

cgidesign

Fishtales

Open Render settings. Go to the Environment Tab. Click on the three line tab at the top left of the window to open and choose Preferences/Show hidden properties.Scroll to the bottom and change the Ground Shadow Intensity to a lower number and that will make the shadow less dark.

thorne2

Fishtales said:

Open Render settings. Go to the Environment Tab. Click on the three line tab at the top left of the window to open and choose Preferences/Show hidden properties.Scroll to the bottom and change the Ground Shadow Intensity to a lower number and that will make the shadow less dark.

Oh, thank you! This is exactly what I was looking for. Never considered that there would be hidden properties, but of course there are. 
You've just made everything a lot easier.