aoMap/Shadows inversed in ThreeJS - three.js

I am currently trying to display a 3D room using Three.JS. I bought the model on SketchFab and I am using its GLTF format.
This model includes "baked-in" shadows using an occlusion map and a specular glossiness map.
I do not plan on having dynamic cast shadows so those baked shadows are just fine.
The model is properly imported using the GLTFLoader but my issue arise when I try to light my scene. I set up a basic HemisphereLight and for some reason all my shadows and lit areas are inversed as you can see in the screenshot below:
Screenshot
All the areas that are supposed to be shadows are lit and all the areas that are supposed to be lit are shadows.
I've been trying to solve this for a while now and have no idea where this behaviour is coming from. I also tried to use online GLTF viewer to see if there was any problem with the model itself but everything looks fine:
Screenshot 2

Related

Move a camera inside a GLTF exported with blender using ThreeJS

I'm working with game dev. He has implemented all the boardgame using Blender. He also added some sprites inside directly and linked the sprite to the Camera inside Blender so that when this camera moves, all the sprites will move accordingly to always face the Camera.
Now my question is, how can I implement this using react-three-js. I see that I can export the Camera object from blender (after exporting the GLTF with the Camera inside) and see it in my GLTF in threejs (under gltf.cameras[0])
My question is, How can I change the camera position of the GLTF (not a copy in threejs) so that I can keep the rules he added for the sprite to always face the camera?
Any constraints created in Blender will not be included when exporting files to other formats. Those would need to be recreated in three.js. In this case I'd recommend using gltfjsx to create a JSX representation of your model, and then using the <Billboard /> component to keep objects facing the camera.
If you have many (100+) sprites, it may be necessary to export them as points, and then assign a THREE.PointsMaterial that applies whatever appearance you need with a texture. Those points will face the camera automatically, as shown in this example.

I can't get the aoMap showing in three.js using a glb/gltf asset

I’m having a hard time getting an aoMap working in three.js…
I have a glb asset with an aoMap on the red channel or something. When I bring it into to the babylon viewer, I can see the ao just fine, but it wont show up in the three.js viewer or my project. I think this has something to do with a second set of uvs, but I can't find a resource that involves doing that on top of using the gltf loader… I really don't know what to do here. Any response would be greatly appreciated!
Here is my code (I’m using a html-canvas as the texture)
And I get the model’s geometry and diffuse texture (all white) as desired, but the aomap isnt showing…
code
babylon viewer
three.js viewer
working application with shadows included in diffuse
not working, diffuse is just white, and aoMap is not showing
You're right about needing a second set of UVs. The reason behind this is that diffuse textures often repeat (think of a brick wall, or checkered t-shirt). AO shading, however, is more likely to be unique on each part of the geometry, so it's almost never repetitive. Since this often would need an alternative UV mapping method, the default is to use a second set of UVs.
You could do 2 things:
Re-export your GLTF asset with a duplicate set of UVs.
Duplicate existing UVs in Three.js by creating a new BufferAttribute in your geometry:
// Get existing `uv` data array
const uv1Array = mesh.geometry.getAttribute("uv").array;
// Use this array to create new attribute named `uv2`
mesh.geometry.setAttribute( 'uv2', new THREE.BufferAttribute( uv1Array, 2 ) );
.getAttribute and .setAttribute are methods of BufferGeometry, if you want to read more about them.

ThreeJs and Blender model without texture

I'm new to both Blender and ThreeJs and searched a lot before asking. I created a model with Blender and esported it as .dae so I can load it in the html canvas. The problem is that only the model is loaded and not the textures. I'm doing something wrong or it's the loader that somehow causes the problem?
Here is the sample:
http://provasitimek.herobo.com/firstImport2.html
and the code:
https://github.com/MarcinKwiatkowski1988/learningThreeJs/tree/master/ThreeJs_and_blender
PS. the blender version is 2.70 (so maybe the problem lays here?)
PS2: So, after many attempts, these are my conclusions:
to get the color of the object, you have to choose the Blender renderer and not Cycles renderer
the export to the file .dae is not realy significant, should working with all options (or at least I didn't find any differences between files exported with different options)
if you use Blender renderer and any basic materials (Basic, Lambert, Phong) you get only the color on the object rendered in threeJs: so, for example, if you apply a trasparency to you object on blender, you will not see it on the rendered object on threeJs
with my current level (i just started to learn threeJs and blender 2 weeks ago) this is as far as I can help. Hope someone with higher skills like #mrdoob would figure out what the problem is
THREE.js does not pair models and textures until you actually make a mesh. Export The model and texture separately, load them separately and call
new THREE.Mesh(blenderGeometry,blenderTexure)

Messed up UVs and Lightmap

I want to bake my model lightmap in blender then load them all in three.js.
So in blender i set two uvs for each objects and baked ambient occlusion in second uv. finally i exported whole scene via three.js exporter into js file.
(exporter has problem that the baked texture goes for diffuse-map not light-map which is correctable by editing exported js file).
But the problem is when i load js with SceneLoader, the textures especially for my floor goes wrong, like upside down.
here is my test files: Test Light Map
So is there something wrong with my blender file or ...? Which loader i should use for it?
Thanks.
I just upload some images to see what i mean:
Messed up textures:
After edit js file, it's get better. but still there is problem at the edges:
And specially at floor, the light-map goes wrong:
Ok, i don't know why, but it seems my uvs was messed up in blender. i did some recaculate normals and flip normals in blender and now textures map fine on objects.
But i still need to edit exported scene to change map:texture.png to lightMap:texture.png.
[EDIT]
Actually this is a bug related to three.js scene exporter: Blender Exporter - Scene Exporting
[Final Answer]
The problem was about my model which had a negative scale in blender. i select my model, hit crtl+a then choose scale. now everything's fine.

Three.js shadow map stripes in each light (now simplified, and with jsfiddle!)

I'm trying to create, modify and update (directional only for now) lights and shadowmaps dynamically. The light, shadow and shadow camera helper gets updated correctly as I move the light around or change shadow properties, except from the light's point of view, everything behind the origin (0,0,0) is shadowed for no apparent reason.
Screenshots:
http://i.imgur.com/n4AHvle.png
http://i.imgur.com/l0uaZHD.jpg
http://i.imgur.com/brKwCof.jpg
http://i.imgur.com/a6dqMGo.jpg (new, with spotlight)
You can see a scene with car and a piece of ground, they belong to a geometry imported with ColladaLoader. The problem is with shadowmapping, the car throws shadow correctly, but there are stripy shadows on the ground even though there is nothing else than the car obscuring light.
If I add more similar lights, they also have the same 4 stripes. They also appear with spotlight. If I change shadow map resolution, the stripes' size changes relative to each other, but there seems to be always four of them, spaced from center to both directions.
EDIT: JSFiddle here: http://jsfiddle.net/cL3hX/1/ There shouldn't be any shadows in the scene, unless some new geometry is introduced inside the shadow camera frustum.
Couple of notes on the fiddle:
I have r55, but the demo is r54 because jsfiddle apparently does not yet have r55.
I could only reproduce this with a Collada file. So it probably has something to do with the model. I created a simple cube in Sketchup 8, and tried to export it with various collada options.
In the JSFiddle I could only reproduce the bug with a file exported with "doublesided faces" -setting enabled. In my own application code, I do have the same bug on models created with or without that setting enabled, but in the fiddle, the bug seems to be triggered only when "doublesided faces" are exported. Anyway I do need to somehow show backsides of faces, because the tool I'm developing must work with Sketchup exports, and it's very hard to make models in Sketchup without having a mess of frontsides/backsides visible.
The very simple Collada file is included in the JSFiddle as javascript variable. Here's a download link for the same file: https://dl.dropbox.com/u/14489569/shadowmapdemo.dae
The problem is your Collada model.
Your "plane" is actually multiple coplanar faces back-to-back in a single geometry.
It's no wonder there are artifacts.
Replace it with a THREE.CubeGeometry.

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