vr初学资料（VR beginner data）.doc

vr初学资料(VR beginner data)
Introduction to -ray (1) -- global Guang Zhaoming
The first part of the calculation of diffuse reflection phase (open GI)
Vray cocoa two ways available to calculate the diffuse reflection
1) direct force calculation, the calculation results are directly mixed with the direct illumination results. Then there is no I-map diagram on the screen
Note: the calculation methods of primary reflection, two times and more than two reflections are different. For a rebound, subdivs is increased
The rendering time rate for two times and two times more rebound, increase the subdivs rendering time increased as a
The rebound was obvious
2) I-map calculation, the calculation results into a I-map map
I- map is a ray map, which mainly displays diffuse light, which is not directly related to material (shade) performance, texture, ray tracing, material and texture,
The control of these representations is the parameter under Image sampler (Anti-aliasing) in Vray, that is, the parameters under Image sampler (Anti-aliasing)
Not only controls the anti aliasing effect, also control the material and texture features
In the GI calculation of I-map
The first step of Vray from the light source emitting HSPH light out of the scene to each pixel, each of the light touch objects in the scene after,
According to the material characteristics on the I-map rebounded, the mul value of a rebound is actually the first rebound of the intensity of the light, saturation, brightness amplification factor in front of
The second step of the second rebound sub determine the number of rebound light, if HSPH is 10, sub is 1, so that is the second rebound,
The 10 light bounces back only one light, the three four bounce is the same as the two bounce. When HSPH is 10, sub is 20, and the two bounces,
10 light anti pop 20 rally before light, three times four times and two times the same bounce bounce of the light
Note: different methods for calculating two times three times and