Help with AI shadowmatte in Maya

your going to need to be more specific, what render engine, what is your lighting setup etc.

Generally speaking - shadows are usually a result of the global lighting environment, so if thats a dome light as an example you can control the shadow intensity by adjusting the gamma of the light.

O.k. setup is:

AiSkydome -> load Hdri -> make plane -> Ai shadow matte -> Arnold Renderer

the shadow doesn't adapt to the hdri, it always stays the same i can't use another light like e.g. spotlight

I dont use maya/arnold but the principle should be the same. When using a HDRI is there a node you can plug in to control the gamma of the image? This will lighten/darken the shadows.

I've tried a lot and since this morning I've watched countless videos on youtube, no video can help. as I said, I only want to make the shadow lighter or darker and not the model!

After a quick look, try plug in a gamma correct node before your HDRI.

As I said - shadows are the result of global lighting. Which means you need to control the gamma of your image (if using a HDRI) to push the black values up/down (light/dark). This is fundamental knowledge, not program specific.

Yes, I try around in the settings but it doesn't work, and if I add another light, nothing happens, Maya is a little different

Have you tried this with multiple HDRIs? Some HDRIs cast strong shadows and some cast soft shadows.

I play with all settings but nothing happens :/ can someone please explain to me how i can adjust the shadow of my background image with shadow matte in maya, setup is above

soo, so! you cannot change the shadow. But you can render the shadow separately and edit it in Nuke or Photoshop, for example.

@3Dcargo I agree! but I'm very disappointed with Autodesk for offering something like this. the scene setup can be done in a few seconds, but you can't change the shadow? so it's all just a joke and useless, what's the point? I've emailed Autodesk and am still waiting for a response from Autodesk support. I'm mad, have a nice day!

OK. the error is and that's a little crazy. only load the spotlight and then only the aiskydome and it works. I only load the aiskydome and then the spotlight, nothing happens on my system I can adjust the shadow with the spotlight, everything works great.

@3dcargo thanks for the video link, it wasn't shown to me during my search

well this video has now contributed to the solution but steered me in the right direction. I take this sequence: Arnold -> Render Settings -> AOVs -> shadow_diff -> Photoshop -> substract this technique is enough for me to adjust the shadows of the image background exactly.