Each material is a vraymaterial within a vray2sidedmaterial. Each of the original 5 blades of grass were assigned one of these material IDs at random before they were scattered. The main material for the grass is a multi-sub object with 3 materials within it. You can also use scatter by Peter Watje, advanced painter, Forest by Itoosoft, Groundwiz Planter or 3dsmax particles. Note: I use vrayscatter (a commercial plugin but well worth the money) to scatter the proxies. 3dsmax uses about 2 gig memory for this scene and each view rendered pretty quickly considering I had vrayfog and depth of field on. Longer grass - some stats: approx 8000 polys per proxy x 1000 proxies = approx 8 million total polygons. The vraycomptex map is set to minimum so that it combines the two maps by always using the darkest rgb value. The first version is for concave creases, the other for convex creases by ticking 'invert normal'. I then combine 2 versions of the vraydirt map inside a vraycomptex map. It can also be modified to affect only areas directly below 3d features.Ī - Shows vraydirt using it's default settings (dirt equal on all sides)ī - Shows vraydirt using settings to force the dirt to work only in a downward directionĬ - As b, but with 'invert normal' tickedĭ - b and c used within a vraycomptex map, set to minimumīy experimenting with the distribution, falloff and z-bias values, I managed to get the downward effect I was looking for (exact settings in screen grab below). Used in it's basic form, with default settings, vraydirt can be used to add a general darkening around edges/corners in your 3d model. A very useful application of the vraydirt shader in Vray is to make materials look dirty/weathered. A quick tutorial on adding dirt to specific materials in Vray.