Problems with shadows

[Karkadann]

umm....................I got Photo Shop Elements and the only thing I do is is change the color and size of a few textures, minor editing

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page 301 in the waking maze came from Photo deluxe 4.0 and a Real Myst print screen

So this may take a while for me to figure out assuming I can do this in Elements.
It does sound like a challenge I have not been able to figure out the subtract/add part
however I did noticed a few other ages with the same tiling issue, and even if I cant figure it out im sure this tutorial will be well received. by those who can

TY

[Christian Walther]

I have no idea about the capabilities of Photoshop Elements, but if it has layers, “linear dodge” and “linear burn” blending modes, and a Gaussian Blur filter, you should be good to go. Otherwise I recommend trying Gimp.

The instructions I gave do assume a certain familiarity with image processing software – I don’t have time to write a complete tutorial for beginners, but if you have detail questions that you can’t solve by experimenting or reading documentation, don’t hesitate to ask here or on IRC.

By the way, I have in the meantime figured out a quicker but less accurate way that may be useful for experimenting to find a good blur radius before doing the final version using the complicated but precise method above:

1. If your application has a high-pass filter:
   1. Apply the high-pass filter to the image
   2. Blend a layer of 50% gray with 50% opacity onto that
   If not:
   1. Invert the image, blur it, and blend that 50% with the original image
2. Blend the result using mode “linear light” onto a layer of the average color of the original image.

[Jojon]

@Christian Walther:

I have used that technique (the more primitive blur-invert-mix variant) once or twice, but now that I see your choice of words, it makes me wonder whether there exists actual FFT implementations... Do you know of any?

[Christian Walther]

now that I see your choice of words, it makes me wonder whether there exists actual FFT implementations... Do you know of any?

I remember seeing one years ago in a scientific image processing application. I think it was NIH Image. Nowadays I’d be inclined to use MATLAB (or Octave) for such things. I imagine there could be Photoshop plugins too.

[Jojon]

Thank you, CW.

Ah yes... I do suppose scientific image processing would be the first place to look.
I also notice that the MATLAB people even offer a ready-made application, specifically for such, although it still looks like something intended for people packing degree-level knowledge, rather than Joe User. :)

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[Karkadann]

Been taking a break on the Stonehenge to work on an iron chandelier for a different age, (I figure a all the lights should drown out the shadows ) and just got back to it and remembered one of the issues I could never figure out is iv got smooth shadows on the grass and chunky shadows on the stones

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Any body got a solution to this one?


I haven't fixed the grass yet but as long as I have a solution to it I can always do that before the next update

Thanks

[Calena]

If you don't mind my suggestions, there are a couple of things that could add realism to this scene. I'm assuming the large ground shadow is coming off another stone? If so, the stone in this shot would block that shadow, with lighter shadowing going up the stone and a second much smaller and lighter shadow starting off the bottom of the stone visible in this shot. What angle is your light set at? These shadows are so long and dark, the current light source appears to be very low and very bright. If the light source is raised to be more perpendicular to the stones, it would probably be much easier to create realistic shadowing.

Another thing that helps (depending on how many hours/days/weeks you want to spend on the scene) is to blend the grass up into the stones, rather than having a sharp cutoff between the two textures.

[Karkadann]

I like the second idea, It will definitely keep me out of every bodies hair for a long time, but the mesh on the stones is not flat and it produces the same chunky shadows on itself if I move the light to a higher angle

[Christopher]

You can try to raise the resoltion of the lightmap attached to the stone. This should refine the shadows. The standard resolution is (if I remeber correctly) 128x128. This definetly to low for these stones. I think you should use at least 512x512.

Christopher

[Calena]

I like the second idea, It will definitely keep me out of every bodies hair for a long time, but the mesh on the stones is not flat and it produces the same chunky shadows on itself if I move the light to a higher angle

Baking light maps or using a normal map as a light map results in what you refer to as "chunky" shading. In most cases, much better results are achieved by baking ambient occlusion maps. Since I work in Blender and 3dsMax2011, I'm not certain what capabilities your software has, but this is a copied directly from the help files of 3dsMax2011:

Ambient Occlusion (MR) Map

Use an ambient occlusion map when you want the surface information to describe how much ambient light the surface can receive. The ambient occlusion map considers the obstruction of the light by surface contours and surrounding objects. By using the ambient occlusion map when rendering, you do not need to set up special lighting, replace materials on the objects, or use with global overrides because the ambient occlusion map already accounts for these settings.

You can use ambient occlusion maps with or without a Projection modifier and for many different purposes. Use them to mask layers in Adobe Photoshop, for items such as painted edits and texture maps. Also use them as dirt maps, or as masks for reflections or specular light.

Note: By default, the shader used by the Ambient Occlusion bake element excludes the low-resolution object from the ambient occlusion calculations whenever performing projection-mapped texture baking. However, if the Projection Mapping option Include Working Model is enabled, then the occlusion rays will include the working model. In this case, projection rays also include the working model. No undesired blank areas appear on the map, because there are no cases where a projection ray passes though the lo-res model to hit a point on the high-res model that is completely occluded by the low res.
Note: This map is available only when the mental ray renderer is active.

Here's an online tutorial for 3dsMax9 that I found: Online Tutorial. At the bottom of the page are rendered screen shots of the shading results. I think this is what you're trying to achieve.