Forum: Carrara


Subject: Ugly stained glass tutorial

MarkBremmer opened this issue on Sep 14, 2000 ยท 4 posts


MarkBremmer posted Thu, 14 September 2000 at 12:42 AM

Hi all, This is in response to marcuswatts inquiry below about realistic haze. Since light through windows comes up periodically I thought it might be helpful to post this. This was done in Carrara but it works in RD 5.5 as well. First of all, go to the render room and enable 'Light Through Transparency' 1. This light is a warm light (directional in this case though it could be a spot) that will shine through the window to cast the color shadow on the floor. The wall and window are spline objects because it is extremely fast to apply shader to them on multiple sides. (Yes, there are some shader tricks in here too.) 2. Cool blue was used on this directional light to fake illumination in a darkened area. 3. Light Cones do not pass through objects. Objects can cast shadows going 'around' the objects but the 'light rays' will not pass through the object. Consequently, here is an array of spots with distance set to 4 so and drop off set to 100% to avoid light rings on the floor. 4. Light 4 is a spot with shadows turned off to fake bounced light from the floor. The light is under the floor. If shadows are turned on, the light will not pass through the floor. Distance is set to 5 with 100% fall off. Now some shader tricks: The window frame (inside the stone area) has a separate glow channel applied to it for some fake radiosity. That is accomplished in the shader tree by changing the Multi Channel pull down to Layer list. That will give you options of where you can place shaders independently ie. Front face 1, Front face 0, Side face 1, and Side face 0 in this case. I mapped the 'stained glass' tiff to the Side face 0. It is a single Resource shader applied to the Glow channel. That way, the underlying bump and color maps are unaffected. The bricks were created with DigitalCarversGuild.com excellent free shader...duh...bricks. However, there is a little extra work in the bump. Instead of leaving the shader as Bricks by itself I used the Add feature to create two channels. the first channel has the bricks in it. The second channel I chose Add again and split that channel into two. Now with in that I applied the stock Spots bump and in the other, applied LostHorizonsSoftware.com's free noise shader. If this shader stuff is a little unclear let me know and I'll post some screen captures of the shader tree. Hope that you have fun with it! Mark