Chaos Corona Forum
Chaos Corona for Cinema 4D => [C4D] General Discussion => Topic started by: jamieirvin on 2018-11-15, 11:50:15
-
Okay, so I'm scratching my head a bit here. When creating a scene for a montage I will often set the 'direct visibility override' ON with a photo loaded so I can match light and avoid a white fringe in the render.
I have always used a material that has a photo within a corona bitmap shader, nested within a Corona Tonemap Control. This ensures the backplate looks like the original image with no post-effects.
However, in the latest release of Corona, this seems not to be working... If I load the bitmap directly in the diffuse slot (omitting the corona bitmap shader) then the backplate shows in the render. However, without the bitmap shader it looks washed out (example A). If I now load the bitmap within the corona bitmap shader it seems to be "broken". The result is a flat grey backplate in the render (example B).
Could this be a bug or am I missing something here?
-
I've been having a play with this and it seems it's just the corona bitmap shader that isn't working properly. Rather than rendering the bitmap correctly, it averages the diffuse and just renders a flat colour...
I guess this is a bug as this never happened in previous releases?
-
Can you show the material setup for your background? You shouldn't use a diffuse texture for this. The solution is to use CoronaLightMtl with "emit light" option disabled. At least that's how it works in 3ds Max, I'm not entirely sure about C4D.
See: https://coronarenderer.freshdesk.com/support/solutions/articles/5000515605
(the article is a bit outdated, we will have to update it)
-
Can you show the material setup for your background? You shouldn't use a diffuse texture for this. The solution is to use CoronaLightMtl with "emit light" option disabled. At least that's how it works in 3ds Max, I'm not entirely sure about C4D.
See: https://coronarenderer.freshdesk.com/support/solutions/articles/5000515605
(the article is a bit outdated, we will have to update it)
That's a good tip about the light material for the backplate. Just tried it and it does give the desired output, however the image is hugely distorted (see attached)
The material setup before was literally a 'corona bitmap' shader with a bitmap in, within the diffuse. That's it.
But in doing all this, I have found that the 'corona bitmap' shader doesn't work at all... anywhere. it displays correctly within the material browser but renders as a flat colour.
-
ok, update on the distortion error. This appears to by symptomatic of being a distance from 0,0,0.
In image A, the camera is close to the origin on the scene with a 2m cube in shot. The backplate is crisp. Perfect.
If we move the camera some distance from the origin, as seen in image B, the backplate becomes completely distorted... Balls!!