Maya creating shader with cmds does not appear in hypershade - maya

using maya 2014/2015 creating a shader like so:
import maya.cmds as cmds
my_shader = cmds.createNode('lambert', n='mine')
will create this result.
anybody knows how to get that shader to be reflected in the hypershade?

shaders are a slightly different node type:
cmds.shadingNode('lambert', asShader=1)
You'll also need to create a shadingEngine node, what we usually know as ShaderGroups or SG`s:
cmds.shadingNode('shadingEngine', asUtility=1)
and connect the .outColor of the shader to the .surfaceShader attribute of the SG. The SG node is actually a subclass of a Maya set, and to assign objects or faces to it use the sets command.

Adding to the answer for completeness:
In some cases (namely ShaderFx shaders) you need to connect the material to the scene's defaultShaderList1 node's next available plug.
import maya.cmds as mc
material = mc.shadingNode('lambert', asShader=True)
shading_engine = mc.sets(name="%sSG" % material, empty=True, renderable=True, noSurfaceShader=True)
mc.connectAttr('%s.outColor' % material, '%s.surfaceShader' % shading_engine)
mc.connectAttr('%s.msg'%material, ':defaultShaderList1.s', na=True)

Related

Maya Python Mash - How can I add a selection set using Maya Mash API (in python)

Adding the cmds.connectAttr at the end does connect the selection set in Maya in the UI, but that's all it does. It acts as it its not registering.
import maya.cmds as cmds
import MASH.api as mapi
sel = cmds.ls(sl=1, l=1, fl=1)
new_set = cmds.sets(sel, n="custom_set")
obj_name = sel[0].split(".")[0]
shape = cmds.listRelatives(obj_name, s=True, f=1)
print(shape)
shape = "pCylinderShape1" #distribute mesh
cmds.select("|pCylinder2") #main mesh MASH
#create a new MASH network
mashNetwork = mapi.Network()
mashNetwork.createNetwork(name="Custom_placement", geometry="Repro")
shape = "pCylinderShape1"
mashNetwork.meshDistribute(shape, 4)
cmds.connectAttr(new_set+".message", mashNetwork.distribute+".selectionSetMessage")
Closest answer I found was here but I am not a programmer to know what that means.
If anyone can help, I'd much appreciate it.
After a lot of investigation I did manage to find the answer from the provided link.
The code I wrote was only the first part of the solution.
hasMASHFlag = cmds.objExists('%s.mashOutFilter' % (new_set))
if not hasMASHFlag:
cmds.addAttr( new_set, longName='mashOutFilter', attributeType='bool' )
cmds.setAttr( '%s.arrangement' % (mashNetwork.distribute), 4 )
cmds.setAttr( '%s.meshType' % (mashNetwork.distribute), 7 )
Note sure is needed but I noticed when you connect a selection set by default it has an extra attribute called mashOutFilter.
The part that is needed is the .meshType that makes it work.

Calculate the Normal of a vertex in maya with Python

I have a script when I make a light it points to my object. I did this with a normalConstrain. But is there any other way to do this without constrains ?
I think I need to calculate the normal of the closest vertex form my Light ?
But I don't know how to do this, if someone can help me would be nice !
See Screenshot
Here is how I did the NormalConstrain :
myNormalConstrain = cmds.normalConstraint('mySphere','myLight', aimVector = (0,0,1), worldUpType = 'scene',name='NormalConstrainToObject')
The easy way is to create a closestPointOnMesh node an connect it to the worldMesh attribute of your mesh. The only wrinkle is that there's a bug in Maya 2016 (not sure about others) where the normal value coming back from the node is not actually normalized if you are using units other than centimeters. Here's a function which does it:
import maya.cmds as cmds
import maya.api.OpenMaya as api
def get_closest_normal(surface, x, y , z):
node = cmds.createNode('closestPointOnMesh')
cmds.connectAttr(surface + '.worldMesh ', node + ".inMesh")
cmds.setAttr( node + ".inPosition", x, y, z, type='double3')
normal = cmds.getAttr(node + ".normal")
# there's a bug in Maya 2016 where the normal
# is not properly normalized. Not sure
# if it's fixed in other years.... this
# is the workaround
result = api.MVector(*normal)
cmds.delete(node)
result.normalize()
return result
print get_closest_normal('pSphereShape1', 10, 1, 1)
Instead of getting the number and deleting the node as done here, you could keep the node around and connect it's normal attribute to something for live updates. This is a fairly expensive node to update, however, so don't use that version for something like an animation rig without testing performance to be sure it's affordable

How to color a scnplane with 2 different materials?

I have a SCNPlane that I created in the SceneKit editor and I want 1 side of the plane to have a certain image and the other side of the plane to have another image. How do I do that in the Scenekit editor
So far what I've tried to do is adding 2 materials to the plane. I tried adding 2 materials and unchecking double-sided but that doesn't work.
Any help would be appreciated!
Per the SCNPlane docs:
The surface is one-sided. Its surface normal vectors point in the positive z-axis direction of its local coordinate space, so it is only visible from that direction by default. To render both sides of a plane, ether set the isDoubleSided property of its material to true or create two plane geometries and orient them back to back.
That implies a plane has only one material — isDoubleSided is a property of a material, letting that one material render on both sides of a surface, but there's nothing you can do to one material to turn it into two.
If you want a flat surface with two materials, you can arrange two planes back to back as the doc suggests. Make them both children of a containing node and you can then use that to move them together. Or you could perhaps make an SCNBox that's very thin in one dimension.
Very easy to do in 2022.
It's very easy and common to do this, you just add the rear as a child.
To be clear the node (and the rear you add) should both use the single-sided shader.
Obviously, the rear you add points in the other direction!
Do note that they are indeed in "exactly the same place". Sometimes folks new to 3D mesh think the two meshes would need to be "a little apart", not so.
public var rear = SCNNode()
private var theRearPlane = SCNPlane()
private func addRear() {
addChildNode(rear)
rear.eulerAngles = SCNVector3(0, CGFloat.pi, 0)
theRearPlane. ... set width, height etc
theRearPlane.firstMaterial?.isDoubleSided = false
rear.geometry = theRearPlane
rear.geometry?.firstMaterial!.diffuse.contents = .. your rear image/etc
}
So ...
///Double-sided sprite
class SCNTwoSidedNode: SCNNode {
public var rear = SCNNode()
private var thePlane = SCNPlane()
override init() {
super.init()
thePlane. .. set size, etc
thePlane.firstMaterial?.isDoubleSided = false
thePlane.firstMaterial?.transparencyMode = .aOne
geometry = thePlane
addRear()
}
Consuming code can just refer to .rear , for example,
playerNode. ... the drawing of the Druid
playerNode.rear. ... Druid rules and abilities text
enemyNode. ... the drawing of the Mage
enemyNode.rear. ... Mage rules and abilities text
If you want to do this in the visual editor - very easy
It's trivial. Simply add the rear as a child. Rotate the child 180 degrees on Y.
It's that easy.
Make them both single-sided and put anything you want on the front and rear.
Simply move the main one (the front) normally and everything works.

Using PyMEL to set the "Alpha to Use" attribute in an object of class psdFileTex

I am using Maya to do some procedural work, and I have a lot of textures that I need to load into Maya, and they all have transparencies (alpha channels). I would very much like to be able to automate this process. Using PyMEL, I can create my textures and hook them up to a shader, but the alpha doesn't set properly by default. There is an attribute in the psdFileTex node called "Alpha to Use", and it must be set to "Transparency" in order for my alpha channel to work. My question is this - how do I use PyMEL scripting to set the "Alpha to Use" attribute properly?
Here is the code I am using to set up my textures:
import pymel.core as pm
pm.shadingNode('lambert', asShader=True, name='myShader1')
pm.sets(renderable=True, noSurfaceShader=True, empty=True, name='myShader1SG')
pm.connectAttr('myShader1.outColor', 'myShader1SG.surfaceShader', f=True)
pm.shadingNode('psdFileTex', asTexture=True, name='myShader1PSD')
pm.connectAttr('myShader1PSD.outColor', 'myShader1.color')
pm.connectAttr('myShader1PSD.outTransparency', 'myShader1.transparency')
pm.setAttr('myShader1ColorPSD.fileTextureName', '<pathway>/myShader1_texture.psd', type='string')
If anyone can help me, I would really appreciate it.
Thanks
With any node, you can use listAttr() to get the available editable attributes. Run listAttr('myShaderPSD'), note in it's output, there will be two attributes called 'alpha' and 'alphaList'. Alpha, will return you the current selected alpha channel. AlphaList will return you however many alpha channels you have in your psd.
Example
pm.PyNode('myShader1PSD').alphaList.get()
# Result: [u'Alpha 1', u'Alpha 2'] #
If you know you'll only ever be using just the one alpha, or the first alpha channel, you can simply do this.
psdShader = pm.PyNode('myShader1PSD')
alphaList = psdShader.alphaList.get()
if (len(alphaList) > 0):
psdShader.alpha.set(alphaList[0])
else:
// No alpha channel
pass
Remember that lists start iterating from 0, so our first alpha channel will be located at position 0.
Additionally and unrelated, while you're still using derivative commands of the maya.core converted for Pymel, there's still some commands you can use to help make your code read nicer.
pm.setAttr('myShader1ColorPSD.fileTextureName', '<pathway>/myShader1_texture.psd', type='string')
We can convert this to pymel like so:
pm.PyNode('myShader1ColorPSD').fileTextureName.set('<pathway>/myShader1_texture.psd')
And:
pm.connectAttr('myShader1PSD.outColor', 'myShader1.color')
Can be converted to:
pm.connect('myShader1PSD.outColor', 'myShader1.color')
While they may only be small changes, it reads just the little bit nicer, and it's native PyMel.
Anyway, I hope I have helped you!

Create widget array using Qt Designer?

In Qt Designer I'm creating multiple labels (for instance):
my_label1
my_label2
my_label3
...
my_label n
Then if I want to hide them I do this:
ui->my_label1->hide();
ui->my_label2->hide();
ui->my_label3->hide();
...
ui->my_labeln->hide();
However I would like to define the labels like
my_label[n]
So then I would be able to do this:
for(i=0;i<n;i++)
{
ui->my_label[n]->hide();
}
I read that I can define the widget like:
QLabel* my_label[5];
but is there any way to do the same from Qt Designer?
Thanks in advance!
Finally I decided to do direct assignment:
QLabel* my_label_array[5];
my_label_array[0] = ui->my_label1;
my_label_array[1] = ui->my_label2;
my_label_array[2] = ui->my_label3;
my_label_array[3] = ui->my_label4;
my_label_array[4] = ui->my_label5;
Then I can do for instance:
for(idx=0;idx<6;idx++) my_label_array[idx]->show();
for(idx=0;idx<6;idx++) my_label_array[idx]->hide();
for(idx=0;idx<6;idx++) my_label_array[idx]->setEnabled(1);
for(idx=0;idx<6;idx++) my_label_array[idx]->setDisabled(1);
etc...
Then I was able to perform iterations. I believe is not the cleanest way to do it but given my basic knowledge of Qt is ok for me.
Thank you very much for your answers and your support! This is a great site with great people.
Instead of creating an explicit array, you may be able to name your widgets using a particular scheme and then use QObject::findChildren() on the parent widget to get a list of the widgets you are after.
If you only want to hide widgets, you can put all the widgets you want to hide in an invisible QFrame (set frameShape to NoFrame) and hide them all by calling setVisible(false) on the QFrame. This may cause some unwanted side effects with layouts so you may have to tweak some size policy settings.
In case you are wanting to hide controls so that you can simulate a wizard type UI, you may want to check into QStackedWidget.
I have another dirty workaround for this:
in header file
// .hpp
class UiBlabla : public QWidget {
...
QLabel** labels;
};
in source file
// constructor
ui->setupUi(this);
labels = new QLabel*[10]{ui->label_0, ui->label_1, ui->label_2, ui->label_3,
ui->label_4, ui->label_5, ui->label_6,
ui->label_7, ui->label_8, ui->label_9};
I haven't seen anything in QtDesigner to do that, but there are a couple of relatively easy ways to get that behavior.
1) Simply store the my_labelx pointers (from QtDesigner) in an array (or better, a QVector):
QVector<QLabel*> my_labels;
my_labels.push_back(ui->my_label1);
my_labels.push_back(ui->my_label2);
Then you can iterate through the QVector.
for(int i=0; i < my_labels.size(); ++i) {
my_labels[i]-> hide();
}
// or with QFOREACH
foreach(QLabel* label, my_labels)
label->hide();
There is a little setup needed in terms of adding all the labels to the QVector, but on the plus side you only do that once.
2) Depending on the layout of your gui, you could have all your labels be children of a container object and iterate through the children

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