Digital Art Zone

What exactly are the differences?

When I render a scene with Ray Trace and shadows on it actually seems to render shadows but as far as I can tell when I render with Deep shadow it doesn’t look any different from doing on OpenGL render with shadows, there are no actual shadows cast. Am I setting something wrong on my renders?

Deep Shadow Maps, as the name implies, generate a map showing where shadows will fall. That map has a fixed resolution so if you have a large environment or very widely spread smaller items in your scene it’s possible for individual items to be too small to get shadows. Ray tracing actually checks the line of sight from the light to the surface, so it does a much better job of creating shadows (and it also supports features like soft shadows), but at the expense of increased render times (especially where there are transparency mapped surfaces).

Fwiw, I believe the resolution on Deep Shadow Maps is a measly 1024x1024 and it is cropped to perspective.  So if you’re using a 1920x1080 resolution in your scene, your DSM map is only 1024x576 pixels.

is there any way to increase the shadow map size? I know maya has this feature but idk about daz

Not to my knowledge.  You may be able to do it with the external 3Delight Renderer though.

Deep Shadow maps also have a tendency to leave artifacts in a render, especially with transparencies over sss…

I would highly recommend getting yourself a copy of “Digital Lighting and Rendering, Second Edition” (New Riders - 2006) —it doesn’t discuss DAZ Studio (not that I’ve found, anyways), but it has an excellent section covering ray-traced and depth map shadows, among many other topics.

2getit - 05 December 2012 10:02 AM

is there any way to increase the shadow map size? I know maya has this feature but idk about daz

Here are a couple of items in the documentation center that discuss changing sample sizes for deep shadow maps. Hope this helps.

Basic Lighting in DAZ Studio
http://docs.daz3d.com/doku.php/artzone/pub/tutorials/dazstudio/studio-lighting00

Standard Shadows [Light]
http://docs.daz3d.com/doku.php/public/software/dazstudio/4/referenceguide/interface/panes/shader_mixer/bricks/dzshadowbrick/start

I wish someone would do a speaking book for “Digital Lighting and Rendering, Second Edition” so I could get benefit from it. If I had a pound for every recommendation for that book I have seen I would be well off by now. Many folks swear by it.

Szark - 05 December 2012 07:42 PM

I wish someone would do a speaking book for “Digital Lighting and Rendering, Second Edition” so I could get benefit from it. If I had a pound for every recommendation for that book I have seen I would be well off by now. Many folks swear by it.

It’s awesome, even as dated as it is. I believe there’s also a third edition, but I haven’t gotten around to picking it up yet. It’s written in a pretty general way that can apply to many different 3D applications, and then it has examples of how specific applications might implement a particular concept. I really can’t recommend it highly enough.