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Author Topic: Receiving Dark shadows  (Read 5713 times)

DU9759

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Receiving Dark shadows
« on: September 22, 2008, 06:00:09 PM »
I am using Forest Pack Pro 3.03b.

My scene is using Mental ray with Mr Sky and Mr Sun.

All appeared to work well including shadow casting. however I am having a problem. The shadows cast on the forest pack trees are excessively dark, and there appears no way of lightening them. I tried to increase the self-illum factor in the mental ray properties of the forest properties but this only lightens the parts of the plants that are not in shade. This does not make sense to me as I thought this would lighten even the areas that received no light. The dark shadows are being cast by other seen objects and by forest objects. However only forest objects receive the dark shadows. the other objects are only receiving light shadows.

I tried increasing the Max. Trace Depth, Max. Reflections and Max. Refractions to 30, 6, 30 but this mad no difference.

I will attach an image of a rendering. You will see the dark shadows to the plants along the hedgerow to the right of the lawn.

Is there any way of correcting this?

Thank you.

Regards

Joseph

iToo

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Re: Receiving Dark shadows
« Reply #1 on: September 22, 2008, 09:57:28 PM »

This is a problem of Forest Material with Mental Ray when Final Gathering is enabled. Unfortunately, there is no way to fix it without disabling FG or patching the plugin.

Please, try the attached Forest shader. It's patched to solve this issue, so you may finish up your scene. However, we must do extensive tests yet, before including it in Forest 3.04b.

To install it, unzip the file, and copy the FShader3.dll file to <maxdir>\mentalray\shaders_autoload\shaders, where <maxdir> is your 3DS main folder.

With this shader and using Final Gather, i suggest not to use self-illum. You may set in "Material" rollout, "self-Illum factor" parameter to 0% for each Forest object, instead modifying the materials.

Please, post here the results, to know if the patch solves the issue.
Carlos Quintero
iToo Software

DU9759

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Re: Receiving Dark shadows
« Reply #2 on: September 23, 2008, 10:20:52 AM »
Thanks!

This updated shader seems to help greatly. Take a look a the before and after picture below.

The dark shadows have disappeared.

The self-illum factor appears to be disabled. I turned it down to 0 and it made no difference to the tree brightness. I also noticed that the trees are much brighter by default. In the before picture I needed to turn the self-illum factor to 350% and the tree are still not as bright as the with the new shader set to 0%.

Thanks!

Kind regards

Joseph

iToo

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Re: Receiving Dark shadows
« Reply #3 on: September 23, 2008, 05:16:05 PM »

If the light is perpendicular to the the trees, the self-illum factor would has not effect on this scene. We use it in a different way that 3DS, so the result may be different.

The trees are brighter because the effect of Final Gathering over them (new on this shader). Probably, in Forest 3.04b we will include a parameter to modify the Final Gathering illumination on the trees, so the users may adjust it.
Carlos Quintero
iToo Software

DU9759

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Re: Receiving Dark shadows
« Reply #4 on: September 24, 2008, 03:46:12 PM »
With the new shader the trees look too bright in the renderings and there appears to be no way of adjusting there brightness with out individually adjusting there materials. Do you know of a better way? When will Forest 3.04b be released?

Thanks!

Joseph

iToo

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Re: Receiving Dark shadows
« Reply #5 on: September 24, 2008, 05:36:48 PM »

No, sorry. With this shader is not possible to adjust the Final Gathering illumination on the Forest objects.

We must test the plugin under all possible conditions, so we will need some days before releasing Forest 3.04b. If you like, post here your scene (only the trees, you may remove non-essential objects) and we will include it in our tests.

Carlos Quintero
iToo Software

iToo

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Re: Receiving Dark shadows
« Reply #6 on: October 10, 2008, 06:18:55 PM »
Hi,

We just released Forest Pro 3.04b, that includes a new parameter (Material->Irradiance Color) to adjust the effect of Final Gathering.

The default value is a gray color that works fine for most of scenes using MR Sun + Final Gather with a "Self-illum factor" of 0%.

Carlos Quintero
iToo Software

DU9759

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Re: Receiving Dark shadows
« Reply #7 on: October 11, 2008, 12:15:33 PM »
Great!!!

Thanks!!!

Enjoying using your product!

Joseph

DU9759

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Re: Receiving Dark shadows
« Reply #8 on: October 11, 2008, 12:21:49 PM »
Download link in User Panel is not working for me.

Joe

iToo

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Re: Receiving Dark shadows
« Reply #9 on: October 11, 2008, 01:24:34 PM »

Sorry, we are making some changes to the User Panel and the link was broken. Please, try again, it's already fixed.
Carlos Quintero
iToo Software