Render effect

[Simon Edmondson]

 

I'm rendering a series of frames for the water spout in the current short. The sequence is being rendered as tga files with an alpha channel with the intention of compositing it within the scene.

 

As the render goes through I noticed this strange effect in the shadow and wondered what might have caused it and how to avoid it future ? It appears to be showing the polys the splines approximate too ? The spline rings are far less substantial then the lines suggest. ( think there are 4 in the head of the spout.

 

Multi pass on at 16, toon lines set to 0.2, bias at 20%, default surface properties.

OSX 10.68 on Imac, V15.

 

Any help gratefully received

regards

simon

[robcat2075]

Can you embed that and put up a PRJ that does that shot?

[Simon Edmondson]

Can you embed that and put up a PRJ that does that shot?

 

Robert

Thank you for your reply. The render is still going through but, I will try to do that when its finished.

regards

simon

[Mechadelphia]

 

I'm rendering a series of frames for the water spout in the current short. The sequence is being rendered as tga files with an alpha channel with the intention of compositing it within the scene.

 

As the render goes through I noticed this strange effect in the shadow and wondered what might have caused it and how to avoid it future ? It appears to be showing the polys the splines approximate too ? The spline rings are far less substantial then the lines suggest. ( think there are 4 in the head of the spout.

 

Multi pass on at 16, toon lines set to 0.2, bias at 20%, default surface properties.

OSX 10.68 on Imac, V15.

 

Any help gratefully received

regards

simon

 

Hi Simon,

 

I think that this is actually a bug with no practical workaround that I could work out.

 

The render time polygons are showing up in silhouette inside of the shadow.

 

It occurs while using the toon renderer and ray traced shadows. I'm still trying to sort the exact conditions that cause what you are encountering for a bug report. I have reported a somewhat related bug at A:M Reports (ID# 0006339). That report addresses the jagged transition from light to shadow that you see in your render. I've held out on reporting the one you ran into until after A:M v18 gets released.

 

You could try to render a separate shadow pass with the standard renderer and then composite back to your toon render (minus the rendered toon shadows) but that will take a bit of experimenting on your end to get a look that you are happy with.

 

If you work out a workaround in the meantime please share your results.

[Simon Edmondson]

Mack

 

Thank you very much for your reply and help.

I've encountered a similar problem before but can't remember the details. Its not an insurmountable problem for what I have in mind to use it for ( they are going to be 'smudged' in Pshop , but it would be good to be without the bug. In an earlier scene in the short there was a pronounced jagged shadow on a rock and, I now gather it was a problem with the toon render ?

 

Here's the shortened project with everything taken out but the water column. I checked the material settings under properties and the only values set appear to be the toon lines and the bias. There was a roughness setting but I deleted that and it made no difference to the render problem.

Thank you for your help.

regards

simon

 

Water_Spout.prj

[Simon Edmondson]

Following Mack's suggestions, I converted the light to a klieg and used Z buffer rather than ray traced shadows.

This was the result.

 

 

Tried it in V17 and the same problem remained ?

regards

simon

[Mechadelphia]

Following Mack's suggestions, I converted the light to a klieg and used Z buffer rather than ray traced shadows.

This was the result.

 

 

Tried it in V17 and the same problem remained ?

regards

simon

 

Hi Simon,

 

You're welcome.

 

Do you mean that you also are seeing the same type of bug in v17 when using z-buffered shadows or do you mean raytraced shadows in v17? I have not seen that occur with the z-buffered ones but I have never really used that kind of shadow as much.

 

I don't think that the z-buffered shadows are going to produce a shadow that is as well defined or as dark as the ray traced one in the toon renderer.

 

I'm sorry for not being more clear about that. I meant to suggest rendering a raytraced shadow with the standard renderer separately and then composite that back to you toon rendered image. I did not mean doing that with the z-buffered shadow (unless you prefer that).

 

If you separate the shadow pass in A:M's compositor using the OpenExr format and light buffers you can clearly see the problem in the shadow pass when using the toon renderer. I don't recall at the exactly at the moment but the problem is less evident when using raytaced shadows with the standard renderer or not really existent at all.

 

You don't have to use the OpenExr format (in the compositor) but it might make it a little easier to manage.

 

As for your question about the jagged shadow on your rock... Yes, that is a rendering issue that occurs with the toon renderer.

 

I've run into the same issue as you in my Clark WIP. I've been working with separate render passes in an attempt to get around it but I still have a little bit work to do with that.

 

I'll post an update there momentarily so that you can see it.

[NancyGormezano]

I don't think that the z-buffered shadows are going to produce a shadow that is as well defined or as dark as the ray traced one in the toon renderer.

 

I think you can probably get the z-buffered shadows to be somewhat dark by tweaking the shadow softness and shadow darkness - I changed the sun to be a Klieg, set the softness of shadow to 5% or lower, left the darkness of shadow = 80%, and the light width softness to 0 (probably didn't need to, not sure it had effect). I also did 5 pass, did not see that 16 pass made a difference (1st image). If it's not dark enough, change shadow darkness to 100%.

 

It appeared to me that setting shadow softness to 1% made the demarcation between light & dark too raggy. 16 pass did seem to look a little better in this case (2nd image).

[Simon Edmondson]

...

 

Do you mean that you also are seeing the same type of bug in v17 when using z-buffered shadows or do you mean raytraced shadows in v17? I have not seen that occur with the z-buffered ones but I have never really used that kind of shadow as much...

 

You don't have to use the OpenExr format (in the compositor) but it might make it a little easier to manage.

 

As for your question about the jagged shadow on your rock... Yes, that is a rendering issue that occurs with the toon renderer.

 

I've run into the same issue as you in my Clark WIP. I've been working with separate render passes in an attempt to get around it but I still have a little bit work to do with that.

...

 

Mack

Thank you for your reply and help.

No, my mistake. I tried with the ray traced settings in V17 as V15 and the result was the same too.

I tried to use EXR and shadow buffers a while back, but it was a bit involved for what was going through at that time, and haven't had the chance to try again as yet. The chance to do that sort of post production work was a little overwhelming to be honest, I'd be tinkering till the cows came home !

regards

simon

[Simon Edmondson]

I don't think that the z-buffered shadows are going to produce a shadow that is as well defined or as dark as the ray traced one in the toon renderer.

 

I think you can probably get the z-buffered shadows to be somewhat dark by tweaking the shadow softness and shadow darkness - I changed the sun to be a Klieg, set the softness of shadow to 5% or lower, left the darkness of shadow = 80%, and the light width softness to 0 (probably didn't need to, not sure it had effect). I also did 5 pass, did not see that 16 pass made a difference (1st image). If it's not dark enough, change shadow darkness to 100%.

 

It appeared to me that setting shadow softness to 1% made the demarcation between light & dark too raggy. 16 pass did seem to look a little better in this case (2nd image).

 

Nancy

Thank you for your reply and help.

Actually I quite like the softness of the Z buffered shadows on the water spot as they worked well against the ray traced shadows of the figures and landscape. Happy accidental finding !

Difficult to test by observation but, how hard would the shadows be on a rising column of water?

I still need to learn a lot more about the intricacies of the light settings. Embarrassing because Lighting is one of the things I enjoy the most when watching Film or TV.

regards

simon

[NancyGormezano]

Actually I quite like the softness of the Z buffered shadows on the water spot as they worked well against the ray traced shadows of the figures and landscape. Happy accidental finding !

Difficult to test by observation but, how hard would the shadows be on a rising column of water?

 

Yup, best bet is to try tweaking the settings and see what you like. I like the softer look as well.

 

However if you are trying to get different shadow looks on different models in your scene - you will probably have to work with light lists...lots a luck...but it can be done...