Rendering gets stuck at the вЂњcompiling scene geometryвЂќ stage or at вЂњbuilding Embree static acceleratorвЂќ.

Rendering falls into an endless loop of calculating Light Cache / presampling displacement / Unloading geometry.

Typical symptoms of poorly optimized displacement settings (AKA scene uses too much RAM) Hardware: Intel V2 processor, 2.80 GHz, 128 GB RAM Software: 3dsMax 2017 + V-ray 4.10.02 GI was set to Light Cache + Brute Force, default settings All other settings were left as default.

The test scene contains three boxes with VRayDisplacementMod added. We will use various variants of the scene below for tests. We will use VrayDisplacementMod modifier setup for tests because it has all the options which displacement from render settings provide and more, and it allows you to set displacement options separately for each model in a scene.

Subdivision вЂ“ Similar to the 3D mapping method, with the difference that it applies a subdivision scheme to edges (similar to a MeshSmooth modifier).

The actual raytracing of the displaced surface is done in texture space, and the result is mapped back into 3D space. The displaced surface is rendered as a warped height-field based on that texture map.

2D mapping вЂ“ Bases the displacement on a texture map that is known in advance.

3D mapping вЂ“ A general method that takes the original surface geometry and subdivides its triangles into smaller sub triangles which are then displaced.

We will talk about them at the end of the guide.ДЄccording to the V-ray manual, there are three types of mapping in VRayDisplacement Mod: Performance and other settings вЂ“ These are special settings that affect rendering performance they can be used in rare scenarios for debugging displacement-related issues, like artifacts or unusually high resources usage. They are decisive in the number of resources your scene needs for rendering, and we will optimize them in the next chapters of the guide. Quality settings вЂ“ These set the displacementвЂ™s level of detail, number of subdivisions, and mesh density. Please turn to the other settings listed below instead. Therefore, these values should not be compromised for the sake of optimization. They need to be set to specific values to get the exact look of the displaced model you want. Using the VRayDisplacementMod modifier provides more flexibility in setting up displacement features and managing resources necessary for rendering.Дisplacement features settings вЂ“ These influence render times and RAM used by the scene. The downside of this method is that it can create very heavy meshes that require a lot of RAM to process. It does so by dividing the modelвЂ™s polygons into a much denser mesh during the rendering process, which is either elevated or depressed on an up/down axis based on your chosen texture. ItвЂ™s thus mostly used in computer games to add detail to models while keeping a low polycount.Д¬ontrary to those methods, displacement mapping creates real 3D geometry it casts real shadows and looks realistic from every angle. Like bump mapping though, the effect is purely based on rendering it doesnвЂ™t add real detail to the geometry.

It does the same job as bump mapping, except the details are created based on an RGB color map that encodes the angles of the surface. There are cases where it doesnвЂ™t look all that convincing.ДЄnother method is the normal map (normal bump). You wouldnвЂ™t, for example, see changes to the contour of the object. It does the job for small, finer details, and only in some angles. Instead, it creates an illusion of 3D, вЂњfakingвЂќ it during the render process by having light bounce off simulated features that are not actually there. However, bump mapping doesnвЂ™t create a real 3D structure. By taking the placement of light on the model into consideration, it imitates a sculptural relief on the surface, portraying shadows and highlights to simulate texture and depth. Given this all-important feature in real surfaces, 3D applications quickly incorporated tools in their material editors necessary to generate such an effect. ItвЂ™s this essential trait in materials that make them look interesting and real. Each surface contains a 3D structure through which, slick or rough, we perceive texture by how light bounces off its bumps and scratches. ItвЂ™s not only color or reflection the 3D surface of the material also needs to be reproduced for a realistic look.ДЇirst, letвЂ™s have a look at how displacement works as opposed to bump and normal mapping.

Vray color mapping