Model doesn't display correctly in XNA, ignores some bone deformations Reply Quote Edit
I am very new to 3D modelling, however I am required to do some for a project I have undertaken.
The basic principal is that I need a human model that can be deformed to the users measurements (measured using Kinect, but that is another story!). For example I want to stretch the stomach area for larger users etc.
Using 3Ds Max I have been able to rig a human model using a biped and then add some extra bones to change the stomach:
This all looks well and good, however when I load it into XNA, the stomach deformation has vanished-
I am somewhat at a loss as to why this has happened and any suggestions would be most welcome, or any links to tutorials on how this kind of thing should be done.
Furthermore, when I view the exported FBX in an FBX viewer plugin for QuickTime, the deformations show absolutely fine.
The code for displaying the model (its F# code, converted form a c# example, however I have tried it with the original c# code and get the same results) is:
override this.Draw(gameTime)=
// Copy any parent transforms.
let (transforms:Matrix array) = Array.zeroCreate model.Bones.Count
model.CopyAbsoluteBoneTransformsTo(transforms);
this.Game.GraphicsDevice.BlendState <- BlendState.Opaque
this.Game.GraphicsDevice.DepthStencilState <- DepthStencilState.Default
// Draw the model. A model can have multiple meshes, so loop.
for mesh in model.Meshes do
// This is where the mesh orientation is set, as well
// as our camera and projection.
for e:Effect in mesh.Effects do
let effect = e :?> BasicEffect
effect.EnableDefaultLighting()
effect.World <- mesh.ParentBone.Transform *
Matrix.CreateRotationZ(modelRotation)
* Matrix.CreateTranslation(modelPosition)
effect.View <- Matrix.CreateLookAt(cameraPosition,
focusPoint, Vector3.Up)
effect.Projection <- Matrix.CreatePerspectiveFieldOfView(
MathHelper.ToRadians(45.0f), aspectRatio,
1.0f, 10000.0f)
// Draw the mesh, using the effects set above.
mesh.Draw();
base.Draw(gameTime);
Wonder if anyone has any ideas as to what has gone wrong or any ideas of how to sort this.
Any suggestions would be much appreciated.
Thanks
If you added the extra bones to the stomach, then told max to morph some associated vertices in accordance with the new bones by some weighting factor, then you would need to modify Xna's default content processor to tell it how to build the model to take that into account. By default, it won't.
Look at the Skinned model sample on the app hub: http://create.msdn.com/en-US/education/catalog/sample/skinned_model
All the joints(elbows, knees, etc) morph a bit as the joints flex. Ultimately, you are wanting a single vertex to be influenced by more than one transform.
Related
I've replaced the tree.glb model in the ThreeJS placeground example (https://github.com/8thwall/web/tree/master/examples/threejs/placeground), but it's not showing. It works fine when using tree.glb.
To debug, I've also tried replacing it with the jellyfish-model.glb available in the examples, but it also doesn't show when tapping on the floor plane.
Is there something wrong with my code, or with the .glb models I'm replacing tree.gbl with?
const modelFile = 'tree.glb' // 3D model to spawn at tap
to
const modelFile = 'jellyfish-model.glb' // 3D model to spawn at tap
File structure on github: 8thwall-3js-test-github
Ideally, I'd like to replicate what I've done using Unity+Vuforia in this example (which basically places a .png onto a floor plane): https://www.youtube.com/watch?v=poWvXVB4044
I'd start by looking at the scale of the 3d model. The tree model in the link you provided is quite large, so it's being scaled down in size. See https://github.com/8thwall/web/blob/master/examples/threejs/placeground/index.js#L7-L8
Prove to yourself that the model is being loaded by adding a console.log('model added!') type statement into animateIn() (as that is the model loaded handler)
My guess is that your jellyfish-model.glb is there, just very small. Trying adjusting startScale and endScale to larger values and see if that helps.
I am currently working on ARCore for android. our use case is to load a bigger model in ARCore which is with the size of a building with more than two floors. this single big model will be extended to several floors in the building.
when we load the big model it is scaled to a smaller size by default and we could not zoom out to map/match the model for different floors.
when we tried to set node.getScaleController().setMaxScale(50f); the model gets zoomed and hides at certain point.
AnchorNode anchorNode = new AnchorNode(anchor);
TransformableNode node = new TransformableNode(fragment.getTransformationSystem());
node.getScaleController().setMinScale(0.01f);
node.getScaleController().setMaxScale(50f);
node.getScaleController().setSensitivity(0.1f);
node.setParent(anchorNode);
node.setRenderable(renderable);
node.select();
fragment.getArSceneView().getScene().addChild(anchorNode);
we found a youtube link which is similar to our use case, unfortunately, this is in ARKit and by using models with .scn formats.
https://www.youtube.com/watch?v=FG5SztPF2uY
Can someone please suggest whether this is feasible in Arcore.
Sharing some code snippets to scale this bigger model would be very helpful.
Note: our models are in .obj formats and converted to .sfa and .sfb for using in ARCore.
Hope after setting the max and min scale value you are using
public void setLocalScale (Vector3 scale)
Sets the scale of this node relative to its parent (local-space). If isTopLevel() is true, then this is the same as setWorldScale(Vector3).
I am trying to develop my own mini game engine in Apple metal on a mac and I am stuck at a place where I want to render text on the GPU. I do not have much graphics programming experience and hence I am not sure how to do it. I stumbled upon an article written by warren more using signed distance fields. But I do not know how it works and I am unable to understand it completely (lack of my graphics knowledge) to implement it myself. The blog post has a code sample which is written in obj-c but unfortunately i do not know obj-c. Is there some swift version of it? Or can someone explain / give pointers on how to render text in metal?
I have been down this road before. I think you might find SceneKit useful if you are after 3D text.
If you are OK with using SceneKit to drive your rendering: SCNText with a SCNView.
If you have your own command buffer, and you can get away with blending your text on TOP of the rest of your graphics: you can still use SCNText, by using the render() method of a SCNRenderer to render to encode a scene's render commands onto a command buffer.
If you want to avoid SceneKit's rendering process, I would recommend doing this: create a SCNText in a SCNTransaction like so:
import SceneKit
SCNTransaction.begin()
let sceneText = SCNText(string: text, extrusionDepth: extrusionDepth)
SCNTransaction.commit()
let mdlMesh = MDLMesh(scnGeometry: sceneText, bufferAllocator: yourBufferAllocator)
let mesh = try MTKMesh(mesh: mdlMesh, device: MTLCreateSystemDefaultDevice()!)
This MTKMesh will have three vertex buffers; the first one (0) is a list of positions in packed_float3 format, the second (1) a list of normals in packed_float3 format, the third (2) a list of texture coordinates in packed_float2 format. Just make sure to reflect that in your vertex shader. It will have 1-5 submeshes with their own index buffers, corresponding I believe to front, back, front chamfer, back chamfer, and extrusion side.
Now, if you are after 2D text, you can either use this method above with an extrusionDepth close to zero, or you can harness CoreText directly to do font metrics and render textured quads with a font atlas texture like the commenter suggested.
The ability to understand Objective-C is certainly useful as well, but you may not need it for this problem specifically. I tried to be brief on my explanations since I don't know what your exact goal is with this problem, but I can provide more detail on any of those methods upon request.
I've been working on a project that helps create a virtual reality experience on the laptop and/or desktop. I am using XNA 4.0 on Visual Studio 2010. The current scenario looks like this. I have interfaced the movements of a persons head through kinect. So if the person moves his head right relative to the laptop, the scene seen in the image is rotated towards the left giving the effect of a virtual tour or like looking through the window experience.
To enhance the visual appeal, I want to add a darkness at the back plane. Like the box looks as if it was a tunnel.
The box was made using trianglestrips. The BasicEffect used for the planes of the box is called effect.
effect.VertexColorEnabled = true;
effect.EnableDefaultLighting();
effect.FogEnabled = true;
effect.FogStart = 35.0f;
effect.FogEnd = 100.0f;
effect.FogColor = new Vector3(0.0f, 0.0f, 0.0f);
effect.World = world;
effect.View = cam.view;
effect.Projection = cam.projection;
On compiling the error is regarding some normals.
I have no clue what they mean by that. I have dug the internet hard enough. (I was first under the impression that ill put a black omnilight in the backside of the box).
The error is attached below:
'verts' is the VertexPositionColor [][] that is used to build the box.
How do I solve this error ? Is the method/approach correct ?
Any help shall be welcome.
Thanks.
Your Vertex has Position and Color channels, but is has no normals... so you have to provide vertex has it.
You can use VertexPostionNormalTexture if you don't need the color, or build a custom struct that provides the normal...
Here your are a custom implementation: VertexPositionNormalColor
You need to add a normal (vector3) to your vertex type.
Also if you want Distance fog you will have to write your own shader as BasicEffect only implements depth fog (which while not looking as good is faster)
I am using XNA for a 2D project. I have a problem and I don't know which way to solve it. I have a texture (an image) that is drawn to the screen for example:
|+++|+++|
|---|---|
|+++|+++|
Now I want to be able to destroy part of that structure/image so that it looks like:
|+++|
|---|---|
|+++|+++|
so that collision now will work as well for the new image.
Which way would be better to solve this problem:
Swap the whole texture with another texture, that is transparent in the places where it is destroyed.
Use some trickery with spriteBatch.Draw(sourceRectangle, destinationRectangle) to get the desired rectangles drawn, and also do collision checking with this somehow.
Split the texture into 4 smaller textures each of which will be responsible for it's own drawing/collision detection.
Use some other smart-ass way I don't know about.
Any help would be appreciated. Let me know if you need more clarification/examples.
EDIT: To clarify I'll provide an example of usage for this.
Imagine a 4x4 piece of wall that when shot at, a little 1x1 part of it is destroyed.
I'll take the third option:
3 - Split the texture into 4 smaller
textures each of which will be
responsible for it's own
drawing/collision detection.
It's not hard do to. Basically it's just the same of TileSet struct. However, you'll need to change your code to fit this approach.
Read a little about Tiles on: http://www-cs-students.stanford.edu/~amitp/gameprog.html#tiles
Many sites and book said about Tiles and how to use it to build game worlds. But you can use this logic to everything which the whole is compost from little parts.
Let me quick note the other options:
1 - Swap the whole texture with
another texture, that is transparent
in the places where it is destroyed.
No.. have a different image to every different position is bad. If you need to change de texture? Will you remake every image again?
2- Use some trickery with
spriteBatch.Draw(sourceRectangle,
destinationRectangle) to get the
desired rectangles drawn, and also do
collision checking with this somehow.
Unfortunately it's don't work because spriteBatch.Draw only works with Rectangles :(
4 Use some other smart-ass way I don't
know about.
I can't imagine any magic to this. Maybe, you can use another image to make masks. But it's extremely processing-expensive.
Check out this article at Ziggyware. It is about Deformable Terrain, and might be what you are looking for. Essentially, the technique involves settings the pixels you want to hide to transparent.
Option #3 will work.
A more robust system (if you don't want to be limited to boxes) would use per-pixel collision detection. The process basically works as follows:
Calculate a bounding box (or circle) for each object
Check to see if two objects overlap
For each overlap, blit the sprites onto a hidden surface, comparing pixel values as you go. If a pixel is already set when you try to draw the pixel from the second sprite, you have a collision.
Here's a good XNA example (another Ziggyware article, actually): 2D Per Pixel Collision Detection
Some more links:
Can someone explain per-pixel collision detection
XNA 2-d per-pixel collision
I ended up choosing option 3.
Basically I have a Tile class that contains a texture and dimention. Dimention n means that there are n*n subtiles within that tile. I also have an array that keeps track of which tiles are destroyed or not. My class looks like this in pseudo code:
class Tile
texture
dimention
int [,] subtiles; //0 or 1 for each subtile
public Tile() // constructor
subtiles = new int[dimention, dimention];
intialize_subtiles_to(1);
public Draw() // this is how we know which one to draw
//iterate over subtiles
for(int i..
for(int j ...)
if(subtiles[i,j] == 1)
Vector2 draw_pos = Vector2(i*tilewidth,
j*tileheight)
spritebatch.Draw(texture, draw_pos)
In a similar fashion I have a collision method that will check for collision:
public bool collides(Rectangle rect)
//iterate over subtiles
for i...
for j..
if(subtiles[i,j]==0) continue;
subtile_rect = //figure out the rect for this subtile
if(subtile_rect.intersects(rect))
return true;
return false;
And so on. You can imagine how to "destroy" certain subtiles by setting their respective value to 0, and how to check if the whole tile is destroyed.
Granted with this technique, the subtiles will all have the same texture. So far I can't think of a simpler solution.