I have an plane surface(all the z of vertexes equal to 0.0) with many vertexes, and attached the texture on it with lighting off by:
device->SetRenderState(D3DRS_LIGHTING, false);
And there are shades in the render result.
I tried to turn off the normal too:
device->SetRenderState(D3DRS_NORMALIZENORMALS, false);
It doesn't work also.
Does anybody know what's going on?
I just want the texture shows distorted without any light effect.
And the surface is from tessellated NURBS control points.
The color of texture seems changed by VertexShader, is that possible? and how to solve it?
The pure white texture rendered like below:
http://dl.dropbox.com/u/2318704/image/effect.png
question is changed to directx - texture render result is incorrect
Related
I an rendering a simple box:
MDLMesh(boxWithExtent: ...)
In my draw loop when I turn off back-face culling:
renderCommandEncoder.setCullMode(.none)
All depth comparison is disabled and sides of the box are drawn completely wrong with back-facing quads in front of front-facing.
Huh?
My intent is to include back-facing surfaces in the depth comparison not ignore them. This is important for when I have, for example, a shape with semi-transparent textures that reveal the shape's internals which have a different shading style. How to I force depth comparison?
UPDATE
So Warren's suggestion is an improvement but it is still not correct.
My depthStencilDescriptor:
let depthStencilDescriptor = MTLDepthStencilDescriptor()
depthStencilDescriptor.depthCompareFunction = .less
depthStencilDescriptor.isDepthWriteEnabled = true
depthStencilState = device.makeDepthStencilState(descriptor: depthStencilDescriptor)
Within my draw loop I set depth stencil state:
renderCommandEncoder.setDepthStencilState(depthStencilState)
The resultant rendering
Description. This is a box mesh. Each box face uses a shader the paints a disk texture. The texture is transparent outside the body of the disk. The shader paints a red/white spiral texture on front-facings quads and a blue/black spiral texture on back-facing quads. The box sits in front of a camera aligned quad textured with a mobil image.
Notice how one of the textures paints over the rear back-facing quad with the background texture color. Notice also that the rear-most back-facing quad is not drawn at all.
Actually it is not possible to achieve the effect I am after. I basically want to do a simple composite - Porter/Duff - here but that is order dependent. Order cannot be guaranteed here so I am basically hosed.
On desktop OpenGL, points will sometimes be rendered as circles (if you have set gl_PointSize in the vertex shader). I am tinkering with WebGL and it seems to consistently render points as squares (when gl_PointSize is set). Is there a way to get them to render as circles?
Yes, there is a solution. You can do that using point sprites. Just send texture to shader and using alpha blending cut of unnecessary part of sprite.
Normally (in desktop OpenGL) you may see points rendered as circles when you have got MSAA and POINT_SMOOTH feature enabled.
Below you have links where you can get all informations you need :)
OpenGL ES 2.0 Equivalent for ES 1.0 Circles Using GL_POINT_SMOOTH?
http://klazuka.tumblr.com/post/249698151/point-sprites-and-opengl-es-2-0
I have two functions that I want to combine the results of:
drawAmbient
drawDirectional
They each work fine individually, drawing the scene with the ambient light only, or the directional light only. I want to show both the ambient and directional light but am having a bit of trouble. I try this:
[self drawAmbient];
glEnable(GL_BLEND);
glBlendEquation(GL_FUNC_ADD);
glBlendFunc(GL_ONE, GL_ONE);
[self drawDirectional];
glDisable(GL_BLEND);
but I only see the results from first draw. I calculate the depth in the same way for both sets of draw calls. I could always just render to texture and blend the textures, but that seems redundant. Is there I way that I can add the lighting together when rendering to the default framebuffer?
You say you calculate the depth the same way in both passes. This is of course correct, but as the default depth comparison function is GL_LESS, nothing will actually be rendered in the second pass, since the depth is never less than what is currently in the depth buffer.
So for the second pass just change the depth test to
glDepthFunc(GL_EQUAL);
and then back to
glDepthFunc(GL_LESS);
Or you may also set it to GL_LEQUAL for the whole runtime to cover both cases.
As far as I know, you should render lighting to separate render targets and then combine them. So you will have rendered scene into these targets:
textured without lighting
summary diffuse lighting (fill with ambient color and additively render all light sources)
summary specular lighting (if you use specular component)
Then combine textures, so final_color = textured * diffuse + specular.
Even with high resolution textures (4k*2k) of Earth the mapping of the poles is distorted. Is it possible to place a square texture with the middle directly at the poles of a sphere with THREE.js and rotate accordingly?
Example map: http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?mosaic=Arctic.2012154.terra.4km.jpg
Sorry, no code, looking for a starting point.
Maybe you should 'correct' your rectangular texture to avoid the distortion on the poles.
This link might be of help for that: http://local.wasp.uwa.edu.au/~pbourke/texture_colour/texturemap/
In Cesium, a WebGL globe & map engine, we fixed the poles by creating a screen-space quad over where each pole will be, and using a shader to render the pole correctly. The code is in this pull request. We don't yet offer inlay high-res images, but that's coming.
I am writing simple hex engine for action-rpg in XNA 3.1. I want to light ground near hero and torches just as they were lighted in Diablo II. I though the best way to do so was to calculate field-of-view, hide any tiles and their's content that player can't see and draw special "Light" texture on top of any light source: Texture that is black with white, blurred circle in it's center.
I wanted to multiply this texture with background (as in blending mode: multiply), but - unfortunately - I do not see option for doing that in SpriteBatch. Could someone point me in right direction?
Or perhaps there is other - better - way to achive lighting model as in Diablo II?
If you were to multiply your light texture with the scene, you will darken the area, not brighten it.
You could try rendering with additive blending; this won't quite look right, but is easy and may be acceptable. You will have to draw your light with a fairly low alpha for the light texture to not just over saturate that part of the image.
Another, more complicated, way of doing lighting is to draw all of your light textures (for all the lights in the scene) additively onto a second render target, and then multiply this texture with your scene. This should give much more realistic lighting, but has a larger performance overhead and is more complex.
Initialisation:
RenderTarget2D lightBuffer = new RenderTarget2D(graphicsDevice, screenWidth, screenHeight, 1, SurfaceFormat.Color);
Color ambientLight = new Color(0.3f, 0.3f, 0.3f, 1.0f);
Draw:
// set the render target and clear it to the ambient lighting
graphicsDevice.SetRenderTarget(0, lightBuffer);
graphicsDevice.Clear(ambientLight)
// additively draw all of the lights onto this texture. The lights can be coloured etc.
spriteBatch.Begin(SpriteBlendMode.Additive);
foreach (light in lights)
spriteBatch.Draw(lightFadeOffTexture, light.Area, light.Color);
spriteBatch.End();
// change render target back to the back buffer, so we are back to drawing onto the screen
graphicsDevice.SetRenderTarget(0, null);
// draw the old, non-lit, scene
DrawScene();
// multiply the light buffer texture with the scene
spriteBatch.Begin(SpriteBlendMode.Additive, SpriteSortMode.Immediate, SaveStateMode.None);
graphicsDevice.RenderState.SourceBlend = Blend.Zero;
graphicsDevice.RenderState.DestinationBlend = Blend.SourceColor;
spriteBatch.Draw(lightBuffer.GetTexture(), new Rectangle(0, 0, screenWidth, screenHeight), Color.White);
spriteBatch.End();
As far as I know there is no way to do this without using your own custom shaders.
A custom shader for this would work like so:
Render your scene to a texture
Render your lights to another texture
As a post process on a blank quad, sample the two textures and the result is Scene Texture * Light Texture.
This will output a lit scene, but it won't do any shadows. If you want shadows I'd suggest following this excellent sample from Catalin Zima
Perhaps using the same technique as in the BloomEffect component could be an idea.
Basically what the effect does is grabbing the rendered scene, calculates a bloom image from the brightest areas in the scene, the blurs and combines the two. The result is highlighting areas depending on color.
The same approach could be used here. It will be simpler since you won't have to calculate the bloom image based on the background, only based on the position of the character.
You could even reuse this further to provide highlighting for other light sources as well, such as torches, magic effects and whatnot.