As of r49, Three.js does not support shadows in the Canvas renderer, right?
What I need is a shadow directly below an object, like if the light source was at infinite y (approximately sun at noon).
You can duplicate the object, set the scale.y to 0.001 and use a black color for the material :)
Related
I have a model in Blender 2.8 ( and 2.79 ) with a grass texture on a plane. It's a field. No matter what I set the metalness and roughness to, when viewing it in ThreeJS there's always a whitish sheen on the field when looking at it from certain angles according to the sun position.
I think setting the specular color to black would remove that sheen, but I'm guessing this isn't currently possible to do because ThreeJS StandardMaterial doesn't control specular color..
So, basically, is there anyway to control the specular color on a ThreeJS StandardMaterial?
Use an environment map? Or change the color of your directional light?
i am trying to cast an shadow on an totally transparent plane in SceneKit on OSX. I am struggling with this problem since several hours and do not come to any solution.
My Purpose is to generate an Screenshot of several objects with an transparent background and just the shadow on an invisible Plane.
Do you have any suggestions for me how i can make this with apples SceneKit?
Do i have to program my own shader, can i make this work with shadermodifiers or can i use built in functionallity?
UPDATE:
I find an alternative solution for anyone who needs:
create a white plane under 3D model, note that the color of plane must be pure white.
set blend mode of plane's material to SCNBlendModeMultiply.
set light model of plane's material to SCNLightingModelLambert.
This works because any color multiply white color (1, ,1, 1) return itself And lambert light model will not take account of directional light, So the plane will always be background color which look like transparent. Another benefit of this solution is you don't need change light‘s shadow rendering mode.
For people who used to inspector of Xcode.
According to SceneKit: What's New.
First, add a plane under you model. Then prevent it from writing to colorBuffer.
Second, change your light model's shadow rendering mode to deferred. Notice that you must use light which can cast shadows.
Oily Guo, your solution works. Here the solution is in code:
Configuration of the light source:
light.shadowColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.4)
light.shadowMode = .deferred
And for the floor (ie. SCNFloor underneath your objects):
material.diffuse.contents = UIColor.white
material.colorBufferWriteMask = SCNColorMask(rawValue: 0)
I do not have an answer to your question, however I have a workaround:
Render your scene and keep the image in memory
Change all the materials in your object for pure black, no specular
Change the plane and the sky to a fully white material, lights to white
Render the scene to another image
On the second image, apply the CIColorInvertand CIMaskToAlpha Core Image filters
Using Core Image apply the Alpha Mask to the first render.
You'll get an image with a correct Alpha channel, and transparent shadows. You will need to tweak the materials and lights to get the results you want.
The shadow may become lighter on the edges, and the only way around that is rendering it as yet another image, and filling it with black after the Mask to Alpha step.
Currently in my project lens flare is not visible when behind a transparent object, even if the opacity is set to 0. I try to simulate a glass sphere around the camera - but the lens flare is not visible from inside the sphere. Is it possible to solve this?
I think you need to set sphere material depthWrite to false.
material.depthWrite = false;
When I add to the scene two objects and set their transparency as true with some opacity and using TrackballControls I rotate the scene by mouse, the object which was initially further from camera loses its transparency.
I read that this is Z-buffer problem and further objects from camera will be displayed first. But when I rotate the scene using TrackballControls, camera changes its position, so transparent objects should be displayed correctly. But it is not like that.
Here in this picture - on the right is frontview, on the left is backview which is not displayed correctly:
http://www.foto-ondruskova.cz/Experiment/lenses.jpg
Please, any solutions?
I have come across this problem and setting alphaTest: 0.5 to the material as suggested here solved my problem. But it is hit and miss. Give it a try. Hopefully it works!
Is it possible in three.js to create transparent/invisible plane, which can receive shadows? My aim is to draw some object on 3d canvas without background (so I can see webpage behind the canvas element). I want the object to cast shadows on the background and I thought, if I could make an invisble plane, then webpage background is still visible. Shadows are casted on the plane and it seems like shadows are on the webpage.
Right now I can make a white plane with opacity 0.5 (or similar), but this way the plane is visible. Ideally the plane should be completely invisble (except for shadows).
EDIT: I created an exampled (based on this): http://jsfiddle.net/s5YGu/2/
Here I have opacity 0.5, but you can see the plane. If I set opacity to 0, then the whole plane and the shadows disappear.
I made this work by hacking on basic shader, here is working shader code http://pastie.org/5088640
It has no drawbacks AFAIK, like opacity: 0.1
Yes, you can achieve the effect you want, and it looks pretty good on my machine at least. :-)
Here is a fiddle: http://jsfiddle.net/ZXdV3/25/
There are a couple of issues. First, you will have to set alpha: true in the renderer constructor args.
Second, although I assume you'd like the plane to be completely transparent, you'll have to settle for material.opacity = 0.1, or so.
Third, if you are placing a canvas over the webpage, and you want the web page to be interactive, you are going to have to suppress pointer events in the canvas (I'm not sure if IE supports this, though): container.style.pointerEvents = 'none';
three.js r.67