Jump to content
  • Advertisement
Sign in to follow this  

Flip or mirror model/texture

This topic is 2492 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

I'm trying to understand how to flip/mirror a model, but after hours of researches and tries I didn't get any solution.
The engine that I'm developing is a tile engine in a 3D space (i'm using D3DFVF_XYZ | D3DFVF_TEX1 as vertex), I'm using D3DXMatrixOrthoOffCenterLH(&matProjection, 0.0f, f_viewWidth, -f_viewHeight, 0.0f, 1.0f, 100.0f) to get a good view space for a 2D game.
Currently, when I need to flip the tiles, I set on a vertex created, drawed and deleted every frame, I set TU and TV from x+width to x (for not-flipped tiles I set it from x to x+width). The effect that I get with this is very bad:

I tried also to uses D3DSAMP_ADDRESSU and D3DSAMP_ADDRESSV but with bad results and when I trying to do rotation with matrix, the window is totally empty.
Any idea?

Share this post

Link to post
Share on other sites
Try this :)

D3DXMATRIX MirrorX(-1.0f,0,0,0, 0, 1.0f,0,0, 0,0, 1.0f,0, 0,0,0,1.0f);
D3DXMATRIX MirrorY( 1.0f,0,0,0, 0,-1.0f,0,0, 0,0, 1.0f,0, 0,0,0,1.0f);
D3DXMATRIX MirrorZ( 1.0f,0,0,0, 0, 1.0f,0,0, 0,0,-1.0f,0, 0,0,0,1.0f);

D3DXVECTOR4 VertexPos;
//Set VertexPos.x .y. z from source vertex, .w = 1.0f;

//Flip Vertex over X axis

Share this post

Link to post
Share on other sites

Try this

It doesn't work, the tiles won't show anymore when I negate X or Y.
Basically I need to do a 180° Y rotation to have the mirror effect and a 180° Z rotation to have flip effect right? But there are two questions: to have the mirror effect I need to create another square back to the front square? And to have the flip effect I need to set the center position of the current tile but how? When I try to rotate it, it takes as center coord 0, 0 that in my viewport is the top-left pixel... Basically I can set the position to -width/2 and -height/2, to place the center of the image to 0, 0 do a rotation for example of 45 degree in Z and place the model to x and y but I don't know how. I tried to multiply the transformation matrix (the one that set the center of the sprite in 0,0) with the rotation matrix and with the position matrix, but the result is likes that transformation matrix is not multiplied =\

Share this post

Link to post
Share on other sites


see if it shows now

AWESOME!!! Finally X and Y rotation works!!! What cull mode do exactly?
Oh, I resolved also the rotation's center problem:

D3DXMATRIX matrixFinal;
D3DXMATRIX matrixTemp;
D3DXMATRIX matrixPosition;
D3DXMATRIX matrixBlockCenter;
D3DXMatrixTranslation(&matrixBlockCenter, width/-2, height/-2, z);
D3DXMatrixTranslation(&matrixPosition, x, y, z);
D3DXMatrixMultiply(&matrixTemp, &matrixBlockCenter, &matrix_WorldRotation);
D3DXMatrixMultiply(&matrixFinal, &matrixTemp, &matrixPosition);
d3dd->SetTransform(D3DTS_WORLD, &matrixFinal);

Mmm seems that when I do the rotation, the TU and TV are altered:
All the vertex uses the same texture and a single square has texture coordinates that are multiples of 1.0f/textureWidth*tileDimension and the rotation seems to move the TU/TV by 1.0f/textureWidth/tileDimension (so if the TU goes from 0.01 to 0.05, when I rotate the model using transformation, the final TU is something likes 0.06 to 0.02). It's a bug? A limitation of D3D or simply a bad use of rotation? Edited by Retsu90

Share this post

Link to post
Share on other sites
Sign in to follow this  

  • Advertisement

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

GameDev.net is your game development community. Create an account for your GameDev Portfolio and participate in the largest developer community in the games industry.

Sign me up!