You’re almost done with material work, there are still a couple to fix before you move on to scene animation.. Continue working on your file or you can use the provided file named: “Museum_bldg.max” The scene looks quite decent once rendered. There are however one or two things that need attention: If you recall, the walls of the museum were built in Revit as curtain walls. The upper portion had a defined grid that we removed in Revit to minimize poly count. It was mentioned at that time that a Grid or a Tiling effect can be simulated with the help of materials. This is one topic you still need to tackle. Another problem is the railing on the roof. This is a custom railing of metal with glass panels that was created as a Revit Family. However, not much attention was given to the family materials when this railing was conceived. A closer render shows that the panels on the railing are reflective instead of transparent, as glass should be. You’ll start by fixing this problem first. Go to the Material Editor, you need to take a look at the current railing material. If you want, you can delete the existing nodes. This clears out the space but doesn’t remove applied materials to objects in the scene. Go ahead and sample the railing material. You can plainly see that it’s made of a single material that’s metal-based and reflective. This material is used elsewhere in the scene and works well for handrails and balusters, but not for glass. Zoom in even closer and select the railing object. Enter Polygon mode and select any face that’s supposed to be made of metal, either on the balusters or the semi-circular attachments. In the Surface Properties rollout, notice that these polygons are set to ID #1 Select a glass panel, and notice its ID is set to 2. Because the glass panels and the balusters/attachments have distinct IDs, then it becomes easy to separate their materials. For that, you need to use a Multi/Sub-Object material. Double-click it and set its number of sub-materials to 2, that’s all you need in this example. Now connect the railing’s material out-socket to sub-material ID #1 in-socket. This ensures the railing material affects all faces with ID #1. You still need a glass material for those faces with ID #2. Instead of creating one from scratch, sample the glazing on any part of the project that shows transparent glass. Connect that material to ID #2. Finally, with the custom railing still selected, assign the newly created multi/sub material to it. The railing now behaves better at render time. Sometimes, there may be some artifacts related to transparent materials. Notice how the railing becomes too dark when viewed through the curtain wall. To fix that, you need to increase the Max. Refractions value. This increases render time but sometimes, it needs to be done. A value of 6 should work well here. The doors have a somewhat similar problem to the railings. They have glass panels and a frame. The frame though looks more plastic than metal. This is because it is currently using a non-reflective material, albeit a shiny one. However, the door frames are set to ID #1 and the glass to ID #2, which means you can assign them with the same material used for the railings. It so happens that it’s also the same material used for mullions, making for a better integration of the doors and the curtain walls. You may want to revisit the railings around the plaza and ensure they are also applied with the correct material. You can select the railings and simply apply the reflective material you used for the balusters. This ought to make the render more consistent. Finally, let’s take a look at the opaque portion of the curtain wall. The idea is to use tiled panels, rather than a large plain surface. First, go ahead and sample the material as you have learned to do. Initially, it’s based on a somewhat reflective material, which is fine, but it also has a tad of transparency. That was back when it might have been made of frosted glass. You’ll make it fully opaque instead. Disable transparency and adjust reflectivity to 15 and 25 for direct and oblique situations. You can experiment with these values on your own. To create the tiling effect, you will use a Bump map. Enable Bump map, and for an Image, use the Tiles procedural map. Double-click the new map to edit its properties. You can also enlarge its thumbnail to see it better. It is set to 4×4 tiles which is fine, but you need to specify the dimensions of this 4×4 layout in the real-world. We’ll assume that each tile is 6 feet across, so this gives us a layout of 24 feet. Adjust the dimensions accordingly; you can also make that map visible in the viewport for better feedback. In the Advanced Control rollout, you can make further adjustments, such as making the “grout” between the tiles smaller. Bump maps are based on grayscale values, so you can increase the contrast between the colors. You can also increase the intensity of the bump map at the material level, using the bump slider Zoom out and adjust the scene for a better view. Test render the scene. It should look quite good by now. Experiment a bit more and see if you can make it more interesting by adjusting more materials. See what you can do with that center structure, or with the sunshades at the back. Otherwise, save your scene. In the next movie, you add and animate cars to bring the scene to life.