General Answer to let more Light through Glass
Cycles isnt really great at calculating light paths through glass. But you can help it find your light sources with relatively simple node setups.
Use the Is Shadow Ray output of a Light Path Node to control the factor of a Mix Shader Node. We just mix the Principled Shader with a Transparent Shader (make sure, ...
It's now bpy.context.scene.display.light_direction
I don't know when this was changed, or why there's a mismatch between the python in the info pane and the python interface. I was able to find it by tab autocompleting in the python console. Probably worth filing a bug.
Try something like this - It still needs some shader to handle the transparency, but that doesn't mean you still can't still connect your image as an unshaded input (The plane in the image below is only there to show that there is a shadow gradient being generated by the point light, which is not affecting the texture with transparency):
Don't forget to ...
I had the same issue, but was only able to rid my renders of the rgb artifacts by changing the "Volumetric Lighting" tab's Light Clamping from 0.00 to a higher value just like the light threshold within the "Shadows" tab fixed yours.
You can use any of Blender's pre-packaged lighting environments in your scene.
Starting with a basic material on Suzanne, looks great in Material Preview
Scene doesn't look right in Rendered Preview
Create a split screen, and change one area from 3D Viewport to Shader Editor.
Toggle Shader Type from Object to World.
Ensure Node Wrangler Add-on is ...
Translucent seems to be the good node for this purpose, if you want to make it slightly transparent mix it with a Transparent node.
In Cycles, in the Properties > Object Data panel, you can lower down the sun Angle value if you want a crisp shadow. You can also deactivate the Cast Shadow option:
The Import Images as Planes file selection window has an extensive set of options in a panel on the right. You may have to press N to reveal it.
Here are a few of them. One of the material options is 'Shadeless':
.. which produces the desired characteristics. It does it by using an 'IAP_SHADELESS' group:
..which is worth a look, if you want to see how ...
An Emission shader is propperly able to fix your problem. Here is how to do that:
Go into the shading window.
Delete the Principled BSDF shader.
Add an Emission shader.
Connect the shaders like on this image.
Now it should be working.
You can change the shadow angle with the gizmo that comes up when you click on the cogwheel besides the shadow settings field in the viewport shading options. You need to click-and-drag on the gizmo to move the light direction.
Some might say it's a bit impractical when trying to get a precise angle.
If the lighting gizmo is fully white, it means the light ...
If your colours look weird in render preview then follow any one of the given solutions(solution 2 recommended)
This issue is caused by the 'use lights' option, this option is used if you have light sources close to your drawing to affect the colour.
In the layers panel, you'll need to uncheck "use lights" at the bottom of the layers ...
I suppose that you're using an image texture, in that case you could mix it with an Emission in a Mix Shader, and also use it as the factor of this Mix Shader, so that all the bright parts of the image become emissive (you could also use the Emission inputs of the Principled BSDF but you can more easily control the Strength of the Emission with the following ...