Jump to content
Search In
  • More options...
Find results that contain...
Find results in...

How to rotate OBJ around specific point always?


ctbe
 Share

Recommended Posts

I previously asked this question and I was told to translate, rotate, then translate back. After many hours of debugging trying to understand what was going wrong, I have come to the conclusion that it doesn't work like that. When one rotates using GlStateManager.rotate, all the axes of the OBJ rotate as well. In other words, the final translation will translate in reference to the rotated axis, making it impossible to translate to it's previous position. For example:

 

// Move in the x axis 0.5 (works fine)
GlStateManager.translate(0.5, 0, 0)
// Rotate around the z axis, 45 degrees (code breaks. the object rotates as intended, but all the axes get rotated as well)
GlStateManager.rotate(45f, 0f, 0f, 1f)
// Return the object to its previous position (Doesn't work, translates the object diagonally because the axes changed)
GlStateManager.translate(-0.5, 0, 0)

 

How would one rotate the OBJ without the OBJ axes being rotated?

Edited by ctbe
typo
Link to comment
Share on other sites

Apparently I'm a complete and utter jerk and come to this forum just like to make fun of people, be confrontational, and make your personal life miserable.  If you think this is the case, JUST REPORT ME.  Otherwise you're just going to get reported when you reply to my posts and point it out, because odds are, I was trying to be nice.

 

Exception: If you do not understand Java, I WILL NOT HELP YOU and your thread will get locked.

 

DO NOT PM ME WITH PROBLEMS. No help will be given.

Link to comment
Share on other sites

Thanks for the answer, but I give up. I think no one has ever managed to do a custom chest in minecraft. If they did, they had a thorough understanding of what opengl is doing. I don't.

 

I'll make my chest a simple static block. No animation or anything.

Link to comment
Share on other sites

8 minutes ago, ctbe said:

I think no one has ever managed to do a custom chest in minecraft.

Cough:

http://mod-minecraft.net/iron-chests-mod/

 

In order to rotate around a point you need to translate to the origin by that point's offset from the origin, then rotate, then translate back.

  • Like 1

Apparently I'm a complete and utter jerk and come to this forum just like to make fun of people, be confrontational, and make your personal life miserable.  If you think this is the case, JUST REPORT ME.  Otherwise you're just going to get reported when you reply to my posts and point it out, because odds are, I was trying to be nice.

 

Exception: If you do not understand Java, I WILL NOT HELP YOU and your thread will get locked.

 

DO NOT PM ME WITH PROBLEMS. No help will be given.

Link to comment
Share on other sites

It's okay guys. I appreciate the intention on helping :), but I'm really leaving it since this has been eating me for too long. If anyone asks me to add animation to my chests for when the lid opens and close I'll just tell them I don't know how to do it as I don't understand the GL. Don't worry :). Here is an illustration in 2D of what I meant in my first post that is happening with the gl calls.

 

Spoiler

yIGVfs.png

 

In step 3, all the axes of reference get rotated. Meaning that any translation in the x axis afterwards, will be diagonal. This is 2D, but in minecraft, all 3 axes of reference get rotated together with  the object (x, y, z).

Link to comment
Share on other sites

2 minutes ago, Elix_x said:

So I grabbed the first link on google for what I knew existed. 9.9

Apparently I'm a complete and utter jerk and come to this forum just like to make fun of people, be confrontational, and make your personal life miserable.  If you think this is the case, JUST REPORT ME.  Otherwise you're just going to get reported when you reply to my posts and point it out, because odds are, I was trying to be nice.

 

Exception: If you do not understand Java, I WILL NOT HELP YOU and your thread will get locked.

 

DO NOT PM ME WITH PROBLEMS. No help will be given.

Link to comment
Share on other sites

2 minutes ago, ctbe said:

In step 3, all the axes of reference get rotated. Meaning that any translation in the x axis afterwards, will be diagonal. This is 2D, but in minecraft, all 3 axes of reference get rotated together with  the object (x, y, z).

This is the definition of matrices. Understanding matrices will definitely help you solve this. I recommend watching this:

Linear transformations and matrices | Essence of linear algebra, chapter 3*

Spoiler

 

 

As for how to rotate around an axis, in 3D, you can look at how utility method is implemented in JOML:

https://github.com/JOML-CI/JOML/blob/c312304fefbe757e3d37cba866f5742b3448a85c/src/org/joml/Matrix4f.java#L11379

 

This is generic use case, but now i have to correct you. What you put in the "What is happening" is not correct. Because in both translation, rotation and scaling, coordinates do "the same" what the model does (it is actually the opposite - model does whatever you do to the coordinate system).

That said, the transformations you apply further down in the stack, actually apply to the already transformed coordinates as a whole, so

multiplication_order.jpg

 

  • Like 1
Link to comment
Share on other sites

Why thanks for the references and explanation.

 

I know I said I'm leaving it, but just to show my whole problem, here is the rendering result of my code and the code itself that makes the linked video.

 

Lid Rotation: https://vgy.me/EvxpWl


Chest Body Rotation (how I wanted the lid to rotate): https://vgy.me/NOOLZg


Code... (This code is quite a bit so don't worry if you don't look at it. I'm opting for going static.)

  1. TileEntity (TileEntitySimpleChest.kt)
  2. Block properties
  3. Block (BlockSimpleChest.kt)
  4. TileEntitySpecialRenderer (TileEntitySimpleChestRenderer.kt)
  5. Blockstate JSON (blocksimplechest.json)
  6. Chest Model (simple_chest.obj)
  7. Chest MTL (simple_chest.mtl)
  8. Lid Model (simple_chest_lid.obj)
  9. Lid MTL (simple_chest_lid.mtl)


This was an extension of the tutorial: https://wiki.mcjty.eu/modding/index.php/Render_Block_TESR_/_OBJ-1.12  but I changed a lot of it to fit my purposes. Though the rendering code is pretty much a copy paste.

 

No amount of transformation fixes the problem for me. The problem must be me and I could never identify what I was doing wrong. The code I provided here renders the first video only. The chest body rotation happens if one uses false for the IS_CHEST_LID property in the TileEntitySpecialRenderer... in case you wonder how I shifted from rotating the lid to rotate the chest body in the second video.

Edited by ctbe
Better formatting
Link to comment
Share on other sites

Just as Draco said, you have to translate the lid such that it's origin is world origin, rotate, then translate it back.

Notice GlStateManager.translate(x, y, z) in the beginning of the method. This method translates tile entity in the world view space. Now the origin (0,0,0) is "actually" the XYZ of the tile entity, AKA you're working in local coordinates - coordinates relative to the origin of tile/model. So you have to translate the lid by it's local model coordinates to local origin and back. Ex: GL.trans(-lidModelCoords).rot(rot).trans(lidModelCoords).

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share



  • Recently Browsing

    No registered users viewing this page.

  • Posts

    • Ok, so I did some investigations and after a lot of trial and error, I finally came up with a solution. I will try to explain what I did, and why, for anyone who might need it. From what I understood, implementation will add a depedency for both compiling and runtime (pretty sure it will only include API files for compiling if there are, but I'm not 100% sure), and will resolve any nested depedencies aswell, so its kinda neat if one's mod permenently depends on other's mod or API ! Though I need to control whether a mod is included during runtime or not, so I need to specify the scope of my depedencies. I did some searches, and it turned out that Gradle will consume either jars or source folders regardless, so there is not a specific way to deal with one or the other it seems. I then tried the following and it worked like a charm (modified the commit branch / tags so its pointing to a permanent commit, more info here) ! depedencies { compileOnly 'com.github.lazyMods:baubles:1.10.0.0-1.18:api' runtimeOnly 'com.github.lazyMods:baubles:1.10.0.0-1.18' } But, whenever I try to run, the game crashes with a NoSuchMethod exception, pointing towards a method MenuScreens::m_96206_ called within the Baubles main class during ClientSetup (which is the unmapped name of MenuScreens::register) ; which is clearly a mapping issue. It confused me at first, but now that I think of it it's quite obvious : trying to run the game with uncompiled source files will cause all sorts of issues. And even if Jitpack seems to compile on the go those files, it will lack any metadata expected by Forge or ForgeGradle, so it's no use anyway. The only two solutions I can think of are : Download the mod jar, put it in a libs folder inside your workingDir that you can settup as a local repository, then add that jar as a runtime depedency Use CurseMaven as a repository (as @diesieben07 suggested), and add the correct mod jar as a depedency (more info here) I chose the latter, so now I have the following in my build.gradle file, and it works perfectly (one can even remove the ":api" from the baubles depedency to show the entire mod source files in Eclipse) : repositories { maven { url "https://cursemaven.com" content { includeGroup "curse.maven" } } maven { url "https://jitpack.io" } } depedencies { compileOnly "com.github.lazyMods:baubles:1.10.0.0-1.18:api" runtimeOnly fg.deobf("curse.maven:baubles-366844:3576950") // Points toward Baubles: Reborn? v1.10.0.1-1.18.1 on curseforge.com } I couldn't use CurseMaven straight up as lazynessmind didn't provide a source jar or an api jar on curse forge just yet, so I had to use its Github instead to get the API, hence the struggle. I could have added the mod jar itself as an API, but then I would have to manualy add the source files for Eclipse, which then makes this whole "manage your depedencies solely with Gradle" obsolete...   Thanks for the help, as I could not figure out those things on my own ! I hope that may be usefull to someone some day !
    • I am not sure where in your code the icon and tab name text are rendered.
    • So I've got myself a GUI similar to that of the Advancements screen or the Creative screen where I've got a main screen that renders the window, and tabs that render their own info. Everything works fine and dandy, until I have one of the tabs render text. When that happens, all other text rendered by the screen, along with the tab icon are no longer rendered. There seemingly are no errors, and when I try debugging I can see that each code path is still called so I'm not sure what's going on. So within my screen the main render function looks as follows public void render(MatrixStack matrixStack, int mouseX, int mouseY, float partialTicks) { int i = (this.width - GUI_WIDTH) / 2; int j = (this.height - GUI_HEIGHT) / 2; this.renderBackground(matrixStack); if (maxPages != 0) { ITextComponent page = new StringTextComponent(String.format("%d / %d", tabPage + 1, maxPages + 1)); int width = this.font.width(page); RenderSystem.disableLighting(); this.font.draw(matrixStack, page.getString(), i + (GUI_WIDTH / 2) - (width / 2), j - 44, -1); } this.drawWindowBackground(matrixStack, mouseX, mouseY, i, j); this.renderWindow(matrixStack, i, j); this.drawWindowTooltips(matrixStack, mouseX, mouseY, i, j); } The errant line is within this.drawWindowBackground(matrixStack, mouseX, mouseY, i, j);. Here we render the tab window itself. private void drawWindowBackground(MatrixStack matrixStack, int mouseX, int mouseY, int offsetX, int offsetY) { if (this.selectedTab == null) { fill(matrixStack, offsetX + 9, offsetY + 18, offsetX + 9 + 234, offsetY + 18 + 113, -16777216); int i = offsetX + 9 + 117; drawCenteredString(matrixStack, this.font, EMPTY, i, offsetY + 18 + 56 - 9 / 2, -1); drawCenteredString(matrixStack, this.font, SAD_LABEL, i, offsetY + 18 + 113 - 9, -1); } else { RenderSystem.pushMatrix(); RenderSystem.translatef((float)(offsetX + 9), (float)(offsetY + 18), 0.0F); this.selectedTab.drawTabBackground(matrixStack); RenderSystem.popMatrix(); RenderSystem.depthFunc(515); RenderSystem.disableDepthTest(); } } From there the tab draws itself as follows: public void drawTabBackground(MatrixStack matrixStack) { if (!this.centered) { this.scrollX = 117 - (this.maxX + this.minX) / 2.0D; this.scrollY = 56 - (this.maxY + this.minY) / 2.0D; this.centered = true; } RenderSystem.pushMatrix(); RenderSystem.enableDepthTest(); RenderSystem.translatef(0.0F, 0.0F, 950.0F); RenderSystem.colorMask(false, false, false, false); fill(matrixStack, 4680, 2260, -4680, -2260, -16777216); RenderSystem.colorMask(true, true, true, true); RenderSystem.translatef(0.0F, 0.0F, -950.0F); RenderSystem.depthFunc(518); fill(matrixStack, MAX_WIDTH, MAX_HEIGHT, 0, 0, -16777216); RenderSystem.depthFunc(515); this.minecraft.getTextureManager().bind(background); int i = MathHelper.floor(this.scrollX); int j = MathHelper.floor(this.scrollY); int k = i % 16; int l = j % 16; for(int i1 = -1; i1 <= 15; ++i1) { for(int j1 = -1; j1 <= 8; ++j1) { blit(matrixStack, k + 16 * i1, l + 16 * j1, 0.0F, 0.0F, 16, 16, 16, 16); } } this.renderWindow(matrixStack); RenderSystem.depthFunc(518); RenderSystem.translatef(0.0F, 0.0F, -950.0F); RenderSystem.colorMask(false, false, false, false); fill(matrixStack, 4680, 2260, -4680, -2260, -16777216); RenderSystem.colorMask(true, true, true, true); RenderSystem.translatef(0.0F, 0.0F, 950.0F); RenderSystem.depthFunc(515); RenderSystem.popMatrix(); } And finally we get to the errant line: this.renderWindow(matrixStack);. This method is overridden by each tab and renders the content of the tab. For my tab it is simple, we render a piece of text at the center of the tab. This text renders fine, however it breaks the tab icon and window name. @Override protected void renderWindow(MatrixStack matrixStack) { ITextComponent divineFavourText = new TranslationTextComponent("screen.mesoamericamythology.divine_relationships.favour.divine_favour", this.getRelationship().getDivineFavour()); // x, y, colour // This line breaks the rendering :( drawCenteredString(matrixStack, this.minecraft.font, divineFavourText, MAX_WIDTH / 2, MAX_HEIGHT / 2, Integer.parseInt("FFFFFF", 16)); } Below I have two screenshots. The one on the left is what the UI looks like when I don't draw the string in renderWindow. The right is what happens when I do. I'm a little befuddled at the moment. Hoping someone has more pointers that would help me understand what is going on.
    • User was banned for piracy. Buy the game.
    • Well, the errors seem as though they're tconstruct/jei, have you tried updating those? There are newer versions for 1.16 on curseforge for both of those mods. If you're convinced it's one of your dimensions mods, remove them 1 by one, or remove all and add them back 1 by 1, until you find the culprit.   *edit: what is tlskincape?
  • Topics

  • Who's Online (See full list)

×
×
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy.