View Full Version : Weird skin render

07-05-2005, 11:53 PM
I am quite new to lightwave, or any cg program for that matter. This is the first face i have modeled and below is the first render. As you can see, it is less than desirable. I created a real quick texture in zbrush just to see what i get. I want to know why there are theose splotchy spots on the skin. They were not in the texture itself. I am using monte carlo radiosity with an hdri image world. Any help would be great, as well as any critiques on the model as it is my first. Thanks a ton,


07-06-2005, 12:34 AM
Think of Radiosity as a simulated real world lighting engine. That is, it would be impossible or at least far too processor intensive to actually calulate all of the rays of light that bounce in a scene.

Therefore, radiosity has a setting letting you decide how accruate it will be or how many rays it will try to calulate per evaluation of the scene.


The result of not calculating enough rays is what you see there. Generally this is a result of simply not having enough information and the blotches are, well, what you get.

Regarding image world I have not used it so cannot coment if there are settings to check there as well. There might be. If so, you'll get a response.

But for radiosity there are two peramiters that will help. One, you guessed it Rays Per Evaluation. Up that a bit untill it goes away. (also increases render time, but you guessed that by now)

Also you should enable Shading Noise Reduction. Keep in mind for future reference that SNR will also smooth out shadow mapped shadows from Spot and Distant type lights that can use shadow maps if you have a large fuzzy edge.

A third thing actually would be keep in mind that the radiosity choices go up in terms of accuracy from Backdrop Only to Interpolated which is the most accurate. So you can try that as well.

Render and wait. :)

07-13-2005, 05:46 PM
All of the above .. but also reduce the size of your hdri image. 128x128 is plenty for lighting and blur it as well.

Lighting wise I'd recomend a simple 1 area light at 50% with no intensity fall off, setup with Montecarlo set to about75%, 2x6, 1.

No this is not a great setup, but is a decent enough base to start at and judge textures with. The percentage value of your radiosity is adjusted for your hdri. I usually just use a background colour of 128,128,128.