Rendering an interior scene软件.doc

Rendering an interior scene Home Tutorials Search Keywords interior lighting an interior Note The scene for this tutorial is provided by Wouter Wynen from Aversis http www aversis be For further discussion of this topic see this topic on the V Ray forum Part I Adjusting the GI settings 调整 GI 设置 Part II Rendering with materials 带材质渲染 Part III Rendering the final image 渲染最终图 Part IV Post processing the image 后期处理 Part I Adjusting the GI settings Step 1 First render 第一次渲染 不开GI 1 1 Open the scene which can be found here 打开场景 1 2 Assign V Ray as the current renderer 指定V Ray 为渲染器 Since the default V Ray settings are not very well suited for a fast initial preview we ll make a few quick adjustments before the first render V Ray 默认的设置并不是非常适合快速预览渲染效果 在第一次渲染之前 快速调整一下设 置 1 3 Check the Override mtl option in the Global switches rollout click the button next to it and select a default VRayMtl material 在全局开关选项卡中的全覆盖材质选项上点击 选择VrayMtl材质 1 4 Set the Image sampler type to Fixed 选择图像采样类型为固定 1 5 Set the resolution to 400 x 325 shift F 显示安全框 选择最终输出图像大小为400 325 1 6 Set the Region size in the System rollout to 32 x 32 pixels 在系统选项卡中 设定区域尺寸为32 32像素 1 7 Optionally you can turn on the Frame stamp to print the render time on the image 可选项 打开水印 显示渲染时间 1 8 Render the scene 渲染场景 Step 2 GI preview 打开GI GI 全局光 预览 2 1 Turn GI on from the Indirect illumination rollout 在间接照明选项卡中打开GI 2 2 Select Light map as both the primary and secondary GI engine 选择Brute force 1 46版本前称为Light map 1 5版本为Brute force 为第一GI 引擎 选择 Light cache 灯光缓存 为第二GI 引擎 2 3 In the Light cache rollout set the Subdivs to 500 since we want only a fast preview We ll return this to 1000 for the final rendering 在Light cache 灯光缓存 卷展栏中 设置Subdivs 细分值为 500 如果机器性能差 可以 设置得更低 现在需要的是快速预览 所以值比较低 在最终渲染时 再把这个值设定为 1000 2 4 Set the Interp samples of the light map to 5 for a faster rendering 为了更快速的渲染 设定发光贴图的插值样本为5 2 4 Turn on the Show calc phase option for the light map 打开发光贴图的显示计算过程选项 2 5 Render 渲染 The result is quite noisy but it does give a good idea of what the scene lighting is like 结果的噪点很严重 但是确实显示出来场景中的光线状况 Step 3 Tweaks 场景暗 需要调亮 细微调整 3 1 Since the scene looks too dark we would like to brighten it a bit There are several ways to do this One is to increase the power of the lights However this will make the directly lit areas of the image like the patch of sunlight too bright while indirectly lit regions will remain relatively dark Here is an example of this all lights are x 2 场景太暗了 调亮一点儿 有很多方法可以使用 一种是增加光的强度 然而 这会使得场景 中直接光照射的地方过亮 像阳光照射的区域 太亮 但是间接光照射的区域却还是相对要暗 下面是增加光源强度的实例 所有的光强度都乘2 You can see that the increased light power has made the image brighter and also has increased the contrast of the lighting The scene still looks dark though We can increase the light power even further but this will blow out the directly lit areas too much and will slow down the GI calculations later on So instead of increasing light power we will simply make the material brighter 可以看到 增加了光强度使得场景更亮了 也增加了光的对比度 场景看起来还是要暗 还可 以继续增加光强度 但是会造成直接光照射的区域曝光过度 一片死白 还会减慢GI 计算 过程 所以 不是增加光强度 而是把材质调亮 3 2 Go to the Material Edtior and put the default VRayMtl in one of the slots it shows up as being used in the Environment in the Material Maps browser 在材质编辑器中把默认的VrayMtl 材质放到材质编辑球上 在材质 贴图浏览器中的 环境 部分正在使用的材质中可以找到它 3 3 Make the diffuse color of the material RGB 200 200 200 把默认的固有色调整为RGB 200 200 200 3 4 Render 渲染 The result is much better We still have the same amount of light entering the scene but it is bounced around more and thus increases the overall brightness of the scene 结果好多了 场景中使用的光的量还是一样的 但是反射光更多了 增加了整个场景的亮度 At this point you can adjust the ratio color etc of the lights while getting a relatively fast feedback on the lighting 还可以调整光的比率 颜色等等 在光环境上能快速的看到调整效果 注 这个阶段可以专注 于调整光环境 直到满意为止 Step 4 Better GI 消除光斑 更好的GI 设定 The GI settings that we used are good mostly for fast previews while you are still adjusting the scene Once you have settled on the parameters of the lights it s time to refine the GI solution GI的设定对于快速预览已经够好的了 就可以继续调整场景 比如调整光的亮度 色调 一旦光的参数确定下来 就可以更加细致的调整GI以获得更精致的效果了 4 1 Set the primary GI engine to Irradiance map 设定第一次GI 引擎为发光贴图 4 2 Select a Medium preset for the irradiance map 选择发光贴图的预设为 中 4 3 Turn the Show calc phase option for the irradiance map on 在发光贴图下面 打开显示计算过程选项 4 4 Render the scene 渲染场景 Rendering takes more time now as V Ray needs to calculate a more precise GI solution 渲染花了更长的时间 因为V Ray需要更精确的计算GI Step 5 Better antialiasing and less noise 抗锯齿和降噪 更好的抗锯齿和更少的噪点 The GI looks ok now but we still have no antialiasing and there is noise from the area light at the window We ll deal with those now GI现在看起来不错 但是还没有设置抗锯齿而且还有从窗户这个面光源带来的噪点 现在就来 解决这个问题 5 1 Set the Image sampler type to Adaptive DMC 设置图像采样类型为自适应DMC 5 2 Turn GI off 关闭GI 5 3 Render 渲染 We do have antialiasing now but the noise is even worse We ll adjust the DMC sampler to improve that 还有锯齿 噪点更厉害了 调整DMC采样来提高质量 5 4 Set the Min samples of the DMC sampler to 16 and the Noise threshold to 0 002 在 settings 卷展栏里 把DMC采样的最小采样值设定为16 噪点阈值设为0 002 5 5 Render 渲染 The noise is less but there is still some of it Reducing the Noise threshold and increasing the Min samples any more will not help We simply need more samples for the area light One way to do that is to go to the parameters of the VRayLight and increase the subdivs However if you have many lights in the scene this is quite a lot of clicking Instead we will use the Global subdivs multiplier to do that 噪点少了 但是还是有一点儿 降低噪点阈值并提高最小采样值将不再有帮助 面光源需要更 多的样本 一种方法是在VrayLight的参数里增加细分 然而 如果场景中有很多灯的话 就要 点击很多次 于是 我们使用全局细分倍增来实现 5 6 Set the Global subdivs multiplier to 4 0 and render 把全球细分倍增设置为4 0 渲染 There is still some noise but we can continue to increase the Global subdivs multiplier until the result is good enough 16 0 seems to be a good value 还是有一些噪点 可以继续提高全局细分倍增的值 直到图的质量足够好 16看起来的效果不 错 5 7 Set the Global subdivs multiplier to 16 0 and render 设定全局细分倍增为16 0 渲染 Step 6 Final rendering with GI 使用GI 最终渲染出图 The increased Global subdivs multiplier affects the irradiance map too so if we render now with GI it will be too slow We ll need to do some adjustments 增加了全局细分倍增后 将影响发光贴图 如果现在渲染 将会很慢 需要做些调整 6 1 Turn GI on 打开GI 6 2 Set the Hemispheric subdivs for the irradiance map to 8 0 to compensate for the increased Global subdivs multiplier 把发光贴图的半球细分设定为8 0 以弥补增加全局细分倍增的调整 6 3 Render 渲染 This completes the first part of the tutorial In the next part we ll add the scene materials 这一部分完成 下一部分 将添加场景材质 Part II Rendering with materials Step 1 Rendering with materials 带材质渲染 1 1 Turn the Override mtl option in the Global switches rollout off 在全局开关卷展栏中 关闭材质覆盖选项 1 2 Turn on the reflection refraction Max depth limit in the same rollout 打开反射 折射最大深度限制 1 3 Turn GI off 关闭GI 1 4 Set the Noise treshold of the DMC sampler to 0 005 for faster previews 设定DMC采样的噪点阈值为0 005 这样可以快一点儿预览效果 1 5 Render 渲染 Step 2 Preview materials with GI on 打开GI 预览材质效果 2 1 Turn GI on 打开GI 2 2 For faster previews set the primary engine to Light cache 要想快速预览 设定第一引擎为灯光缓存 2 3 Render 渲染 At this point you can adjust your scene materials while getting fast previews of how the will look in the scene 在这种条件下 可以调整场景中的材质 快速的看到调整效果 Step 3 Better GI with the materials 带着材质 更好的GI效果 3 1 Set the primary engine to Irradiance map 设定第一引擎为发光贴图 3 2 Set the DMC Noise threshold to 0 002 设定DMC噪点阈值为0 002 3 3 Set the light cache Subdivs to 1000 设定灯光缓存细分为1000 3 4 Set the light cache Sample size to 0 03 this will make the light cache a little smoother and slightly faster 设定灯光缓存的采样尺寸为0 03 这会使得灯光缓存有点儿平滑并且稍微快一点儿 3 5 Render 渲染 This is the final image that we will render at full res in the next part 这就是我们下一步要最终渲染的图 Part III Rendering the final image We now have to render the final image 现在渲染最终图 Step 1 Adjusting V Ray for larger resolution 调整V Ray 出大图 1 1 Set the resolution to 1600 x 1300 设定大图为1600 1300 1 2 Set the render region size to 64 x 64 渲染区域尺寸为64 64 We will need to adjust the irradiance map parameters since we increased the resolution twice we can decrease the irradiance map Min and Max rate by 2 调整发光贴图的参数 由于大图的尺寸变为了原来的4倍 可以降低发光贴图最小和最大比率 为2 1 2 Set the irradiance map preset to Custom 设定发光贴图预设为定制 1 3 Set irradiance map min rate to 5 设定发光贴图最小比率为 5 1 5 Set irradiance map max rate to 3 设定发光贴图最大比率为 3 Step 2 Rendering the final image 渲染最终图 2 1 Set the 3dsmax to save the rendered image For increased precision you can choose a 16 bit image format for example a 16 bit png Optionally you can save to a hdr image in that case you need to select the Unclamped color channel in the V Ray GBuffer rollout 设定3DsMax 保存渲染图像 因为增加了精确度 可以选择保存为16位的图像格式 例如 16位的png格式 也可以保存为hdr格式 那就需要在V Ray Gbuffer 卷展栏中选择 不要剪 掉颜色 通道 2 2 Press the Render button 渲染 2 3 Go out for lunch 出去吃个饭先 The final scene for this rendering can be found here 这张图的最终的场景文件可以在这里找到 Part IV Post processing the image The image looks ok but in most cases you will want it to be a little darker or a little brighter etc Instead of changing the lights and re rendering you can do those adjustments in an image processing program 图看起来还不错 但是大多数情况 可能需要更亮一点儿 或者更暗一点儿 不用从新调整灯 光再渲染 可以在图像后期处理中进行类似调整 For example here is the same image with the gamma value adjusted I used a png file and IrfanView for this purpose but you can use any other software that you feel comfortable with for example HDRShop for hdr files 例如 调整过gamma的图如下 我使用了png格式和IrfanView 但是你可以使用任何其他你喜 欢用的软件 例如HDRShop来处理hdr文件 To add a more photographic feel to your image you can apply some radial darkening of the corners for example like this 为了让图片更具照片感 可以添加一些边角失光的效果 真实世界中 拍照时 物理相机镜头 多少会有这种现象 例如下面这样 SPECULAR BLOOM Before you start 在开始之前 This tutorial assumes a basic photoshop knowledge It is however a very easy to follow and small excersise 这个教程需要具备基本的PS知识 非常容易学 只需要一点点练习 Specular bloom glows or flairs usually appear in real photography around very bright objects This can have various reasons and is sometimes even done on purpose to give the image something extra In CG it is very hard to render in one pass but is very easy to do in post That is what we will do here with the help of Adobe Photoshop Any other digital imaging package will probably be able to do the same thing though In many renderers this is also available as a post process filter 光晕特效 在真实照片中非常亮的物体通常有发光或者闪光的效果 这可能是多种原因造成的 有时可以给图像添加特殊的效果 在CG 计算机图形学 中 在一次渲染中很难渲染出来 但 是很容易在后期中进行处理 也就是下面要做的 使用Adobe Photoshop 任何其他数码图片 处理软件都可以实现同样的功能 在很多渲染器中 都提供了后期滤镜来实现这个功能 Start by opening the original untouched rendering in Adobe Photoshop You can download the image here or use your own image to start with 在PS中打开原始的数码图片 可以从这里下载图片 或者使用之前渲染好的图片 First duplicate the only layer by dragging it to the new layer icon at the bottom of the layer palette 首先 通过拖拽图层到图层面板下边的 新建图层 上 复制一层 Select the magic wand tool and look at its settings I used the default tolerance here but you can adjust this as you wish We will use this tool to make a selection of some bright parts in the scene For example click inside the white of the window To select additional parts hold down shift while you click 选择魔棒工具 看一下它的设置 这里使用默认的容差值 这个值你可以根据需要任意调节 使用魔棒工具选择场景中亮的区域 例如 在窗户中的白色区域点击一下 要选择添加其他区 域 在点击时按住shift键即可 This is what I selected click image to enlarge 这就是我选择的区域 Press ctrl shift i on your keyboard This will invert our selection 按ctrl shift I 选择反转 Turn off the bottom layer make sure the top one is still selected and hit delete Everything is deleted except for our original selection