tailieunhanh - LightWave 3D 8 Lighting Wordware game and graphics library phần 8

Lưu ý: Trong dự án tính năng mới nhất của tôi, tôi sử dụng các biểu thức để làm cho các góc hình nón ánh sáng tự động thay đổi để giữ hình nón ánh sáng chỉ đủ lớn để bao gồm các yếu tố CG. Bằng cách này, khi đèn đã được chuyển đến thiết lập một cảnh, các nghệ sĩ không phải đi qua mỗi ánh sáng để tối ưu hóa góc hình nón. Nó đã được thực hiện tự động. | Tips Tricks n Tutes Note In my latest feature project I employed expressions to make the light cone angle automatically change to keep the light cone just large enough to cover the CG element. This way when the lights were moved to set up a scene the artist did not have to go through every light to optimize the cone angle. It was done automatically. Adding a Skylight Now that we ve covered a bunch of different ways of making key sunlight or moonlight it s time to throw in a secondary light source a fill light as it were. Fill lights are so-named because they fill in the spaces where the key light does not illuminate. When there is sunlight in the sky or moonlight for that matter the most readily available fill light source is usually the sky. During the daytime this often means a bright blue sky. During the night it usually means barely perceptible starlight but we ll deal with that later. The main thing to understand about skylight is that it is by nature omnidirectional and soft. In other words the shadows if any are very soft. This is because the entire sky is one big illumination source so you have light approaching from all directions wrapping around objects and causing very soft sometimes imperceptible shadows. So let s start with the simple cheap tricks we can use to simulate skylight and then move gradually on to the more accurate and more expensive methods after that. Using Ambient Intensity By far the easiest cheapest method of creating any fill light is by throwing in a little ambient intensity. I know I just finished talking about how evil ambient intensity is but hey we re looking for the cheapest method of creating a fill light. It doesn t have to be good just cheap Ambient intensity is something that only exists in the CG world. LightWave just adds whatever percentage of illumination you choose to every surface in the scene. The net effect of high ambient intensity is that objects tend to look flat and fake. Figure shows an image with an .