[1.7.10] Massive rendering glitches with Multiblock OBJ Model

[BenignBanana]

Hi guys,

I'm working on a somewhat complex Mod Project right now and I want to use a custom single model for my multiblock structure. Everything worked fine for a while, until i started noticing massive glitches in the rendering of the models.

 

Here are some screenshots:

 

https://dl.dropboxusercontent.com/u/26616665/2015-03-26_18.45.06.png[/img]https://dl.dropboxusercontent.com/u/26616665/2015-03-26_03.30.39.png[/img]

 

 

This is how the model is supposed to look:

 

 

 

As you can see, the back of the model is rendering over the front (or in picture 2, the second model is rendering over the first).

 

These are the main relevant files, the rest can be found on my https://github.com/Todkommt/Mass-Effect-Ships-Mod:

 

 

TileEntityCustomRenderer:

public class TileEntityEezoCoreBaseRenderer extends TileEntitySpecialRenderer {
    private static final ModelSphere model = new ModelSphere();

    private final DisplayListWrapper wrapper = new DisplayListWrapper() {
        @Override
        public void compile() {
            Tessellator t = Tessellator.instance;
            RenderBlocks renderBlocks = new RenderBlocks();
            renderBlocks.setRenderBounds(0.05D, 0.05D, 0.05D, 0.95D, 0.95D, 0.95D);
            t.startDrawingQuads();
            t.setBrightness(200);
            renderBlocks.renderFaceXNeg(ModBlocks.eezoCoreBase, -0.5D, 0.0D, -0.5D, Icons.marker);
            renderBlocks.renderFaceXPos(ModBlocks.eezoCoreBase, -0.5D, 0.0D, -0.5D, Icons.marker);
            renderBlocks.renderFaceYNeg(ModBlocks.eezoCoreBase, -0.5D, 0.0D, -0.5D, Icons.marker);
            renderBlocks.renderFaceYPos(ModBlocks.eezoCoreBase, -0.5D, 0.0D, -0.5D, Icons.marker);
            renderBlocks.renderFaceZNeg(ModBlocks.eezoCoreBase, -0.5D, 0.0D, -0.5D, Icons.marker);
            renderBlocks.renderFaceZPos(ModBlocks.eezoCoreBase, -0.5D, 0.0D, -0.5D, Icons.marker);
            t.draw();
        }
    };

    public TileEntityEezoCoreBaseRenderer() {
        MinecraftForge.EVENT_BUS.register(this);
    }

    @SubscribeEvent
    public void onTextureChange(TextureStitchEvent event) {
        if (event.map.getTextureType() == 0) wrapper.reset();
    }

    @Override
    public void renderTileEntityAt(TileEntity tileentity, double x, double y, double z, float f) {
        TileEntityEezoCoreMultiblock multiblock = (TileEntityEezoCoreMultiblock)tileentity;

        if(multiblock.isComplete()) {
            GL11.glPushMatrix();

            int diameter = multiblock.getRadius() * 2 + 1;
            GL11.glTranslated(x - multiblock.getRadius(), y + ((multiblock.getRadius() * 2 + 1) * 0.106), z + multiblock.getRadius() + 1);
            //GL11.glScaled(diameter, diameter, diameter);
            GL11.glScaled(diameter * 0.00156493134906993521705858633492d, diameter * 0.00160472945866056441544520009372d, diameter * 0.00156486196352619735413139206991d);

            bindTexture(Textures.Model.CORE_BASE);
            model.renderPart("base");

            bindTexture(Textures.Model.CORE_MID);
            model.renderPart("mid");

            if (multiblock.isActive())
            {
                this.bindTexture(Textures.Model.CORE_ACTIVE);
            }
            else
            {
                this.bindTexture(Textures.Model.CORE_IDLE);
            }

            model.renderPart("core");

            /*model.renderPart("sphere");

            bindTexture(Textures.Model.CORE_BOTTOM);

            model.renderPart("bottom");*/
            GL11.glPopMatrix();
        } else if (multiblock.shouldRenderGuide()) {
            GL11.glPushMatrix();
            GL11.glTranslated(x, y, z);
            float scaleDelta = multiblock.getTimeSinceChange();
            renderShape(multiblock, multiblock.getShape(), multiblock.getColor(), scaleDelta);
            if (scaleDelta < 1.0) {
                renderShape(multiblock, multiblock.getShape(), multiblock.getColor(), 1.0f - scaleDelta);
            }
            GL11.glPopMatrix();
        }
    }

    private void renderShape(TileEntityEezoCoreMultiblock tileEntity, Collection<Coord> shape, int color, float scale) {
        if (shape == null) return;

        TextureUtils.bindDefaultTerrainTexture();

        GL11.glColor3ub((byte) (color >> 16), (byte) (color >> , (byte) (color >> 0));
        GL11.glEnable(GL11.GL_BLEND);
        GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE);
        GL11.glDisable(GL11.GL_LIGHTING);

        for (Coord coord : shape)
            renderAt(coord.x, coord.y + tileEntity.getRadius(), coord.z, scale);

        GL11.glEnable(GL11.GL_LIGHTING);
        GL11.glDisable(GL11.GL_BLEND);
    }

    private void renderAt(double x, double y, double z, float scale) {
        GL11.glPushMatrix();
        GL11.glTranslated(x + 0.5F, y, z + 0.5F);
        GL11.glScalef(scale, scale, scale);
        wrapper.render();
        GL11.glPopMatrix();
    }
}

 

ModelSphere:

@SideOnly(Side.CLIENT)
public class ModelSphere
{
    private IModelCustom modelSphere;

    public ModelSphere()
    {
        modelSphere = AdvancedModelLoader.loadModel(Models.SPHERE);
    }

    public void render()
    {
        modelSphere.renderAll();
    }

    public void renderPart(String partName)
    {
        modelSphere.renderPart(partName);
    }
}

 

 

 

Any help would be greatly appreciated. I'd look into this myself, but I have no experience with OpenGL or 3D Programming in general, so I cant really figure out whats going on.

 

Thank you in advance.

[Draco18s]

Ahh, good ol' depth sorting.

 

How many of those bits have transparent parts?

[BenignBanana]

Ahh, good ol' depth sorting.

 

How many of those bits have transparent parts?

 

Ah, draco, I seem to see you in every thread that I find when googleing forge-related problems =)

Anyways, if you're talking about the model, I don't think it has any transparent parts. I extracted it from the Mass Effect 3 game files, but I had the same problem with a default sphere generated in Maya with a white Texture. If you're talking about transparent blocks, all multiblock parts apart from the base are transparent (for obvious reasons).

[Draco18s]

Ok, so, basically the problem boils down to this:

 

Minecraft is really really bad at Z-sorting.  That is, figuring out what triangles need to be drawn first and which ones not at all.  It's a hard problem in any case, just Minecraft is less-good on average on account of having been programmed by one guy.  It gets away with this accurately on most occasions by assuming that everything is a cube and that triangles don't intersect.  Things get trickier if the triangles in question have any sort of transparency (and if you look at vanilla, it has this problem a lot: particles rendering behind water, and so on).

 

Anyway, if nothing's transparent, then there's some kind of z-sort that's assuming one thing, but which isn't true.  My guess is that the model pieces stick out of their blocks, but are being sorted by where they should be in screen-z-space as if they were contained to their cube volume.

[BenignBanana]

Ok, so, basically the problem boils down to this:

 

Minecraft is really really bad at Z-sorting.  That is, figuring out what triangles need to be drawn first and which ones not at all.  It's a hard problem in any case, just Minecraft is less-good on average on account of having been programmed by one guy.  It gets away with this accurately on most occasions by assuming that everything is a cube and that triangles don't intersect.  Things get trickier if the triangles in question have any sort of transparency (and if you look at vanilla, it has this problem a lot: particles rendering behind water, and so on).

 

Anyway, if nothing's transparent, then there's some kind of z-sort that's assuming one thing, but which isn't true.  My guess is that the model pieces stick out of their blocks, but are being sorted by where they should be in screen-z-space as if they were contained to their cube volume.

 

That's quite unfortunate. Is there any way to fix this problem or do I just have to use a different way of rendering this and/or use a simpler model?

[Draco18s]

Your easiest solutions are to break the model up differently or use a simpler model.

 

You're not likely to fix it by changing the rendering code, unless you want to solve some of the holy grails in computer graphics.

[BenignBanana]

Your easiest solutions are to break the model up differently or use a simpler model.

 

You're not likely to fix it by changing the rendering code, unless you want to solve some of the holy grails in computer graphics.

 

Fair enough. Thanks anyways =)

[TheGreyGhost]

Hi

 

The problem that minecraft 1.7.10 has with z-sorting is only for partially transparent textures  (and it's fixed in 1.8 FYI).

 

Your object has fully-solid-or-fully-transparent texels only, so it should render fine - the z-buffer in OpenGL does all the work for you, minecraft doesn't need to do any sorting at all.

 

Your rendering code appears to turn on alpha blending, which is not needed, so perhaps it also turns off writing to the z-buffer.

Try adding these lines to the start of your rendering:

 

        GL11.glEnable(GL11.GL_DEPTH_TEST);

        GL11.glDepthMask(true);

        GL11.glEnable(GL11.GL_ALPHA_TEST);

        GL11.glAlphaFunc(GL11.GL_GREATER, 0.1F);

 

If that doesn't work, there is probably something wrong with your model.  Round/spherical objects are always a problem.  If you post a video where you walk around the model and look at it from different angles, it will help us diagnose the issue.

 

-TGG

 

PS what is this?

        wrapper.render();

Couldn't find wrapper anywhere.

[BenignBanana]

Hi

 

The problem that minecraft 1.7.10 has with z-sorting is only for partially transparent textures  (and it's fixed in 1.8 FYI).

 

Your object has fully-solid-or-fully-transparent texels only, so it should render fine - the z-buffer in OpenGL does all the work for you, minecraft doesn't need to do any sorting at all.

 

Your rendering code appears to turn on alpha blending, which is not needed, so perhaps it also turns off writing to the z-buffer.

Try adding these lines to the start of your rendering:

 

        GL11.glEnable(GL11.GL_DEPTH_TEST);

        GL11.glDepthMask(true);

        GL11.glEnable(GL11.GL_ALPHA_TEST);

        GL11.glAlphaFunc(GL11.GL_GREATER, 0.1F);

 

If that doesn't work, there is probably something wrong with your model.  Round/spherical objects are always a problem.  If you post a video where you walk around the model and look at it from different angles, it will help us diagnose the issue.

 

-TGG

 

PS what is this?

        wrapper.render();

Couldn't find wrapper anywhere.

 

Man am I glad I left the E-Mail notifications on instead of giving up on this. That worked! You're a lifesaver! Also, it's irrelevant now but wrapper is the anonymous type in the TESR, it's used to render a block guide (I copied the code from OpenBlocks' guide).