I have experience doing still images in Modo and Blender Cycles and this is my first go at UE4.
My big question is how to get a little more realism, I read the Koola thread and he’s great!
In this scene I have no lightmaps, it’s just imported assets from Sketchup and my library.
Q: I don’t understand lightmaps so my question is do I need them, where, and why?
Q: I have used point lights, spots, and emissive geometry but my emissive geometry doesn’t seem to affect the scene?
Any other critiques more than welcome! I look forward to being a part of the UE4 community.
Lightmaps are a way to do realistic lighting–it takes a lot of processing power to calculate realistic lighting so it can be done beforehand using Lightmass with UE4. It renders the lighting to lightmaps, which are just like textures and then it displays them on the mesh. The result is that you get very nice realistic lighting and you get good performance.
The downside though is that it’s static, you can’t use it with moving lights or moving objects since moving things changes the lighting. The difficult part of lightmapping is getting the mesh set up correctly, look for info on that here: Unwrapping UVs for Lightmaps | Unreal Engine Documentation
And there’s more info about Lightmass here: CPU Lightmass Global Illumination | Unreal Engine Documentation
When you use Lightmass for your lighting, you can have emissive textures actually emit light into the scene, just select the object that has the emissive material and then go to its properties and under the Lightmass section check the box that says Use Emissive for Static Lighting
So, in a case like the video I posted I don’t really need light maps or will light maps give my scene a better look? If I understand correctly light maps are more for real time navigation such as game play is that correct? Right now I’m just capturing video from UE4 and compiling into a movie.
Lightmaps are designed to give high quality static lighting with performance in mind. Dynamic lighting like you currently have doesn’t have the option to render higher quality than it already is, lightmaps will give you much nicer looking lighting.
If you’re not really concerned about getting a good realtime framerate but want nicer lighting, look into Nvidia’s VXGI: NVIDIA GameWorks Integration - General Discussion - Unreal Engine Forums
It’s a lighting system that does a higher quality lighting with light bounce, but for realtime applications. For many people they can’t get a good enough framerate using VXGI, but if you’re not concerned about performance you could turn up the quality and even if it takes a full second to render a frame it’ll still be much faster than rendering in a normal 3D application like Blender.
It’s kind of complicated there to set up though–they have their own branch of the UE4 source code and you have to compile their version of the editor that has VXGI.
Okay thanks. So much to learn! UE4 is so different to Modo/Blender rendering and the only reason I am going down this road is to have render times that don’t need render farms like Blender/Modo currently do.
I modeled the apartment in Sketchup and exported as a .fbx model. In the content browser of UE4, after importing the model, when I hover the hand over the apartment asset it says 2 uv channels. I didn’t make uv’s for the apartment model. Does this mean there are two uv channels available?
You’ll have to use lightmaps if you want to achieve realistic results (for arch-viz). Currently, other solutions (vxgi, lvp) really can’t compete performance and quality-wise. Lightmass use photon mapping a bit like a mini offline renderer, just to bake the G.I. G.I is the most important thing in arch-viz. With the right settings and decent lightmaps it can look outstanding. You can try VXGI but imo it’s not worth it. It’s in alpha stage, it’s performance heavy, there is not a lot of help/tutorials about it and there are lots of glitch when you want to record a movie afaik. I tried it but meh, I can wait a lil more!
Once you start being comfortable with the lightmaps workflow, it’s not that hard. I personally use a script to auto-unwrap and flatten all object on channel 2, the lightmap channel and then export to UE4. In Ue4 you crank the settings. You can expect long build time but you only have to do it once!!!
My current project is pretty cool, it takes lightmass 4 hours to build lighting. My settings are pretty high, lightmaps resolution are high. I have 2 computers running through swarm agent to help the process. I record movies with my gtx 980 card which does have shadowplay. I can record at 4k resolution without performance hit. just read the forums and you’ll learn the workflow quite fast man! It’s worth it. Good luck
I have hit a road block though at the moment. I build all my building shells in Sketchup then export as .3ds to bring into Blender and render with Cycles. I exported a model as .fbx, the apartment above, from Blender and UE4 gave me a model has no triangles error and wouldn’t import yet clearly the model is all triangles. Do you have any experience with that combo?
Okay can you tell me if i’m doing this right? In Blender I made two uv’s even for meshes that don’t get an image texture, Blender has a lightmap unwrap uv setting I used, then I exported the models/meshes as .obj into UE4. I only notice a very slight improvement to my scene. Do I need to make adjustments in UE4 like turn on the lightmaps? Or is it all automatic, just export .obj with two uv’s and import to UE4?
Another thing is my scene looks foggy though I have no atmospheric fog and I have a post process volume with I think good settings. The whole scene just doesn’t look like some of the other examples I’ve seen so I must be missing something? It looks low resolution, I have the settings to Epic in Engine Scalability.
-Make sure your mesh is set up so that first UV channel is for your material, second is for lightmaps, export to UE4
-Make sure when you import to UE4 that the option to generate UV’s for lightmaps is not enabled, UE4 can try to generate your lightmap UV’s but it doesn’t do as good of a job because it’s automatic, it’s better to do it by hand.
-If you have two UV channels and you have it set to not generate lightmap UV’s in UE4 then it will assume that the second UV channel is for lightmaps
-By default the lightmap resolution is 32 for each object, you will need to open each mesh from the content browser and change that to what you think is a high enough resolution for your mesh. If your mesh is complex, then it’ll probably need a higher resolution lightmap. If the mesh needs to receive shadows that have lots of details then it will need a higher resolution lightmap.
-After placing the objects in the scene, you can override the default lightmap resolution for an object in its Lightmass properties, that will only apply to that copy of the object in the level.
-Make sure your lights are either Stationary or Static, Static lights only affect static objects, you can have as many as you want but adding more increases your build times. Stationary lights affect both static and dynamic objects, but the light can’t be moving around and only 4 lights can affect a surface at a time (the light will be marked with an X if there are too many stationary lights close together).
-Place a Lightmass Importance Volume that will cover the part of the level that is the most important, this limits the amount of lighting calculation to that area so it doesn’t spend a lot of time calculating unimportant areas.
-Choose your lighting build quality, lower quality will be faster but won’t look as good
-Build your lighting
Thanks for the detailed response, I think I have all that covered. I actually found the uv maps in the UE4 software, somewhere…hahaha…now where did they go.
I pretty much have everything cranked to the max, I’m thinking night scenes are a little tougher to get close to Vray quality and also my material building in UE4 is rudimentary at the moment.
I’ll keep plugin away, fortunately I know a few render engines already so something’s translate to UE4.
In FBX import there’s a checkbox for Generate Lightmap UV’s
For OBJ format import I’m not sure if it has the option
Also–if you have an object you’ve imported with only one UV channel and then you go back to your 3D program and make a second one and import it back to UE4 then you will need to make sure to open the mesh from the Content Browser and set the correct channel to be assigned to the lightmaps, since it won’t know after reimporting to set it to the second channel.
The difficulty of setting up lightmaps is why VXGI is a nice solution—no lightmaps and for the most part the quality is good enough, it’s just a pain to get the source code downloaded and compiled and working.
Q: How would I go about having my skyline texture out the windows always face the camera? Right now the image is mapped to a U shaped box and the perspective is wrong when the camera is at an angle to it.
I would map the image outside to a sphere or cylinder, and make it very large
And remember as far as lights go for archviz–you can use IES files and also each light has a radius so if you want an area light effect you can increase the size. You can also change the length to create a cylindrical light.
I have IES lights above the fireplace. On the subject of lights though, in the two lamps on either side of the couch I had point lights inside the shades and when I increased the radius to spill onto the sofa the light seemed to penetrate the geometry and light the inside of the couch arms which looked totally fake. I removed them and used a two spots in each lamp, one pointing up and one pointing down. I’m trying to come to terms with these lights they seem different than Modo and Blender/Cycles.
Make sure your lights are set to static except for the light from the fire, you only need stationary lights if there’s something that needs to receive light that’s moving around or if the light color/intensity changes. It still looks like from the spot lights from those lamps aren’t casting shadow from the sofa.
I hear you, the shadows just don’t look right. I’ll check the lights. I have the Skylight with an HDRI cranked to 45 to get ambient light in the room. Do you think that’s killing shadows?
