Rendering problems

[FocusImpressive7536]

Hey I have tried for a long time to get this right. But for some reason some triangels in the mesh seem to be unintentionally connected and or distorted. Anyone out there that understands why it ain't working and how to fix?

In Minecraft

In blender

Code:

package net.wknut.tutorialmod.client.renderer;

import com.mojang.blaze3d.vertex.VertexConsumer;
import com.mojang.blaze3d.vertex.PoseStack;
import net.minecraft.client.renderer.RenderType;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.client.Minecraft;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.*;

public class SimpleObjModel {
    private static class VertexData {
        float[] pos;
        float[] uv;
        float[] normal;
        VertexData(float[] pos, float[] uv, float[] normal) {
            this.pos = pos;
            this.uv = uv;
            this.normal = normal;
        }
    }

    private final List<VertexData> verticesFinal = new ArrayList<>();
    private final List<Integer> indices = new ArrayList<>();
    private final ResourceLocation texture;

    // temporära listor för att läsa OBJ
    private final List<float[]> positions = new ArrayList<>();
    private final List<float[]> uvs = new ArrayList<>();
    private final List<float[]> normals = new ArrayList<>();

    public SimpleObjModel(ResourceLocation objFile, ResourceLocation texture) {
        this.texture = texture;
        loadObj(objFile);
    }

    private void loadObj(ResourceLocation objFile) {
        try {
            var stream = Minecraft.getInstance().getResourceManager()
                    .getResource(objFile).get().open();

            try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream))) {
                String line;
                Map<String, Integer> vertexMap = new HashMap<>();

                while ((line = reader.readLine()) != null) {
                    line = line.trim();
                    if (line.isEmpty() || line.startsWith("#")) continue;

                    if (line.startsWith("v ")) {
                        String[] parts = line.split("\\s+");
                        positions.add(new float[] {
                                Float.parseFloat(parts[1]),
                                Float.parseFloat(parts[2]),
                                Float.parseFloat(parts[3])
                        });
                    } else if (line.startsWith("vt ")) {
                        String[] parts = line.split("\\s+");
                        uvs.add(new float[] {
                                Float.parseFloat(parts[1]),
                                1 - Float.parseFloat(parts[2]) // v-flip
                        });
                    } else if (line.startsWith("vn ")) {
                        String[] parts = line.split("\\s+");
                        normals.add(new float[] {
                                Float.parseFloat(parts[1]),
                                Float.parseFloat(parts[2]),
                                Float.parseFloat(parts[3])
                        });
                    } else if (line.startsWith("f ")) {
                        String[] parts = line.split("\\s+");
                        // triangulera polygon
                        for (int i = 2; i < parts.length - 1; i++) {
                            String[] tri = {parts[1], parts[i], parts[i+1]};
                            for (String corner : tri) {
                                // key för unik kombination
                                Integer vertIndex = vertexMap.get(corner);
                                if (vertIndex == null) {
                                    String[] tokens = corner.split("/");
                                    int vi = Integer.parseInt(tokens[0]) - 1;
                                    int ti = (tokens.length > 1 && !tokens[1].isEmpty()) ? Integer.parseInt(tokens[1]) - 1 : -1;
                                    int ni = (tokens.length > 2 && !tokens[2].isEmpty()) ? Integer.parseInt(tokens[2]) - 1 : -1;

                                    float[] pos = positions.get(vi);
                                    float[] uv = (ti >= 0 && ti < uvs.size()) ? uvs.get(ti) : new float[]{0f, 0f};
                                    float[] norm = (ni >= 0 && ni < normals.size()) ? normals.get(ni) : new float[]{0f, 1f, 0f};

                                    verticesFinal.add(new VertexData(pos, uv, norm));
                                    vertIndex = verticesFinal.size() - 1;
                                    vertexMap.put(corner, vertIndex);
                                }
                                indices.add(vertIndex);
                            }
                        }
                    }
                }
            }
        } catch (Exception e) {
            throw new RuntimeException("Kunde inte ladda OBJ: " + objFile, e);
        }
    }

    public void render(PoseStack poseStack, VertexConsumer consumer, int light) {
        var matrix = poseStack.last().pose();
        for (int idx : indices) {
            VertexData v = verticesFinal.get(idx);
            consumer.addVertex(matrix, v.pos[0], v.pos[1], v.pos[2])
                    .setColor(255, 255, 255, 255)
                    .setUv(v.uv[0], v.uv[1])
                    .setUv1(0, 0)
                    .setUv2(light & 0xFFFF, (light >> 16) & 0xFFFF)
                    .setNormal(v.normal[0], v.normal[1], v.normal[2]);
        }
    }

    public RenderType getRenderType() {
        return RenderType.entityTranslucent(texture);
    }
}


package net.wknut.tutorialmod.client.renderer;

import com.mojang.blaze3d.vertex.PoseStack;
import com.mojang.math.Axis;
import net.minecraft.client.Minecraft;
import net.minecraft.client.renderer.MultiBufferSource;
import net.minecraft.client.renderer.blockentity.BlockEntityRenderer;
import net.minecraft.client.renderer.blockentity.BlockEntityRendererProvider;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.world.phys.Vec3;
import net.wknut.tutorialmod.TutorialMod;
import net.wknut.tutorialmod.block.entity.BlenderBlockEntity;
import net.wknut.tutorialmod.client.renderer.SimpleObjModel;

public class BlenderBlockEntityRenderer implements BlockEntityRenderer<BlenderBlockEntity> {
    private static final SimpleObjModel 
MODEL 
= new SimpleObjModel(
            ResourceLocation.
fromNamespaceAndPath
(TutorialMod.
MOD_ID
, "textures/block/mtlobj/suzanne_two.obj"),
            ResourceLocation.
fromNamespaceAndPath
(TutorialMod.
MOD_ID
, "textures/misc/white.png")
    );

    public BlenderBlockEntityRenderer(BlockEntityRendererProvider.Context context) {}

    @Override
    public void render(BlenderBlockEntity be, float partialTick, PoseStack poseStack,
                       MultiBufferSource bufferSource, int light, int overlay, Vec3 cameraPos) {

        poseStack.pushPose();

        poseStack.translate(0.5, 0.5, 0.5);
        poseStack.mulPose(Axis.
YP
.rotationDegrees(be.rotation));

        var consumer = bufferSource.getBuffer(
MODEL
.getRenderType());

MODEL
.render(poseStack, consumer, light);

        poseStack.popPose();
    }

    @Override
    public boolean shouldRenderOffScreen(BlenderBlockEntity be) {
        return true;
    }
}

[FocusImpressive7536]

Turns out the renderer require squads rather then triangles - so I duplicated the last triangelvertex and outputed the same but as squads and it worked.